and when the size of the material removed decreases, the probability of encountering a stress-reducing defect decreases. Since the shear stress and strain in metalcutting is unusually high, discontinuous microcracks usually form on the metal-cutting shear plane. If the material being cut is very brittle, or the compressive ...

stress and strain in metalcutting is unusually high, discontinuous microcracks usually form on the metal-cutting shear plane. If the material being cut is very brittle, or the compressive stress on the shear plane is relatively low, microcracks grow into gross cracks giving rise to discontinuous chip formation. When discontinuous.

The size effect in metalcutting. 877. Figure 3. Variation of shear stress on shear plane when cutting. SAE 1112 steel (after Backer et al. 1952). Horizontal and vertical forces were measured for a number of depths of cut(t)when machining the same-sized surface as in grinding. The shear stress on the shear plane (τ) was ...

In stationary sheet metalcutting processes, like guillotining and slitting, the sheet is cut progressively from one end to the other. This in contrary with transient processes (blanking) where the sheet is cut at once. Where transient shearing processes can be modelled in 2-D (plain strain or

For thermal dismantling and cutting of metallic components, as electric arc, water jet cutting method was developed that can be used for underwater cutting work up to a depth of 20 m. Short-circuiting of a continuously fed electrode wire in contact with the metal generates an electric arc which induces partial melting of the metal, and the water jet surrounding the wire rinses away the molten material, thus making a continuous kerf in the material. The method was also tested and modified to allow larger area, surface cutting and removal of metallic surface coatings. This is achieved by melting parts of the surface with the electric arc and subsequent rinsing by the water jet. The cutting and melting depth for surface removal can be accurately controlled by the operating parameters chosen. (orig./DG) [de

This paper draws from the 'plasticity and friction only' view of metalcutting to the presentation of new modelling strategies based on the interaction between finite elements and modern ductile fracture mechanics. The overall presentation is supported by specially designed orthogonal metalcutting experiments that were performed on Lead test specimens under laboratory-controlled conditions. Comparisons between theoretical predictions and experimental results comprise a wide range of topics such as material flow, cutting forces and specific cutting pressure. The paper demonstrates that while material flow and chip formation can be successfully modelled by traditional 'plasticity and friction only' analyses, the contribution of the fracture work involved in the formation of new surfaces is essential for obtaining good estimates of cutting forces and of the specific cutting pressure

In the frame of an european contract, the feasibility of the underwater cutting with a CO 2 laser power is studied. The aim of this work is the dismantling metallic structures of reactors pools. The paper analyzes the general concept of the experimental device, the underwater cutting head, the experimenting vessel, examples of cuttings in dismantling situation with a 500 W CO 2 laser, and examples of cuttings with a 5 kW CO 2 laser. (author). 2 refs., 9 figs., 2 tabs

By the use of solid matter as additives in cutting tooths it is now also possible to cutmetals (steel, high-alloy steel, titanium, aluminium, lead). The same standard high-pressure elements for the generation of a water jet are used to cutmetals, glass, and ceramics. But within the tool the water jet first of all enters a mixer chamber where it takes in a predosed abrasive by the action of an injector. At the exit end of the mixer chamber, the jet is concentrated again. New applications of this 'Paser' system (particle-stream-erosion cutting process, a registered trade mark), which is also called abrasive jet process, are in aviation and space travel, nuclear technology and so forth. (orig./HP) [de

A model for the plastic deformation that occurs in metalcutting, based on dislocation mechanics, is presented. The model explains the fundamental deformation structure that develops during machining and is based on the well known Cottrell-Stokes Law, wherein the flow stress is partitioned into two parts; an athermal part which occurs in the shear fronts (or shear bands); and a thermal part which occurs in the lamella regions. The deformation envokes the presence of a cellular dislocation distribution which always exists in the material ahead of the shear process. This 'alien' dislocation distribution either exists in the metal prior to cutting or is produced by the compressive stress field which operates in front of the shear process. The magnitude of the flow stress and direction of the shear are shown to be correlated to the stacking fault energy of the metal being cut. The model is tested with respect to energy consumption rates and found to be consistent with observed values.

The cutting of metals has long been described as occurring by laminar plastic flow. Here we show that for metals with large strain-hardening capacity, laminar flow mode is unstable and cutting instead occurs by plastic buckling of a thin surface layer. High speed in situ imaging confirms that the buckling results in a small bump on the surface which then evolves into a fold of large amplitude by rotation and stretching. The repeated occurrence of buckling and folding manifests itself at the mesoscopic scale as a new flow mode with significant vortex-like components-sinuous flow. The buckling model is validated by phenomenological observations of flow at the continuum level and microstructural characteristics of grain deformation and measurements of the folding. In addition to predicting the conditions for surface buckling, the model suggests various geometric flow control strategies that can be effectively implemented to promote laminar flow, and suppress sinuous flow in cutting, with implications for industrial manufacturing processes. The observations impinge on the foundations of metalcutting by pointing to the key role of stability of laminar flow in determining the mechanism of material removal, and the need to re-examine long-held notions of large strain deformation at surfaces.

Decommissioning of commercial nuclear power plants presents technological challenges. One major challenge is the removal of large components mainly consisting of the reactor vessel, steam generators and pressurizer. In order to remove and package these large components nozzles must be cut from the reactor vessel to precise tolerances. In some cases steam generators must be segmented for size and weight reduction. One innovative technology that has been used successfully at several commercial nuclear plant decommissioning is diamond wire sawing. Diamond wire sawing is performed by rotating a cable with diamond segments attached using a flywheel approximately 24 inches in diameter driven remotely by a hydraulic pump. Tension is provided using a gear rack drive which also takes up the slack in the wire. The wire is guided through the use of pulleys keeps the wire in a precise location. The diamond wire consists of 1/4 inch aircraft cable with diamond beads strung over the cable separated by springs and brass crimps. Standard wire contains 40 diamond beads per meter and can be made to any length. Cooling the wire and controlling the spread of contamination presents significant challenges. Under normal circumstances the wire is cooled and the cutting kerf cleaned by using water. In some cases of reactor nozzle cuts the use of water is prohibited because it cannot be controlled. This challenge was solved by using liquid Carbon Dioxide as the cooling agent. The liquid CO 2 is passed through a special nozzle which atomizes the liquid into snowflakes which is introduced under pressure to the wire. The snowflakes attach to the wire keeping it cool and to the metal shavings. As the CO 2 and metal shavings are released from the wire due to its fast rotation, the snowflakes evaporate leaving only the fine metal shavings as waste. Secondary waste produced is simply the small volume of fine metal shavings removed from the cut surface. Diamond wire sawing using CO 2 cooling has

Full Text Available Strained environment is a global problem. In metal industries the use of coolant has become more problematic in terms of both employee health and environmental pollution. It is said that the use of coolant forms approximately 8 - 16 % of the total production costs.The traditional methods that use coolants are now obviously becoming obsolete. Hence, it is clear that using a dry cutting system has great implications for resource preservation and waste reduction. For this purpose, a new cooling system is designed for dry cutting. This paper presents the new eco-friendly cooling innovation and the benefits gained by using this method. The new cooling system relies on a unit for ionising ejected air. In order to compare the performance of using this system, cutting experiments were carried out. A series of tests were performed on a horizontal turning machine and on a horizontal machining centre.

Principal Investigator NAVFAC Engineering and Expeditionary Warfare Center, EV11 Date Reviewed By: Name Internal Reviewer(optional) Date: Reviewed...is the oxy- fuel metalcutting, a hot combustion process that forms visible particulate matter (PM) emissions. Since the beginning of its program in...generation of the alternative fuel is created from virgin methanol instead of the original virgin ethylene glycol. The reason for this switch was because

Using in situ high-speed imaging, we unveil details of a highly unsteady plastic flow mode in the cutting of annealed and highly strain-hardening metals. This mesoscopic flow mode, termed sinuous flow, is characterized by repeated material folding, large rotation, and energy dissipation. Sinuous flow effects a very large shape transformation, with local strains of ten or more, and results in a characteristic mushroomlike surface morphology that is quite distinct from the well-known morphologies of metal-cutting chips. Importantly, the attributes of this unsteady flow are also fundamentally different from other well-established unsteady plastic flows in large-strain deformation, like adiabatic shear bands. The nucleation and development of sinuous flow, its dependence on material properties, and its manifestation across material systems are demonstrated. Plastic buckling and grain-scale heterogeneity are found to play key roles in triggering this flow at surfaces. Implications for modeling and understanding flow stability in large-strain plastic deformation, surface quality, and preparation of near-strain-free surfaces by cutting are discussed. The results point to the inadequacy of the widely used shear-zone models, even for ductile metals.

Hollow needle tool cutsmetal honeycomb structures without damaging adjacent material. The hollow needle combines an electrostatic discharge and a stream of oxygen at a common point to effect rapid, accurate metalcutting. The tool design can be varied to use the hollow needle principle for cutting a variety of shapes.

Purpose: To improve the cutting performance to a level as comparable with that in air, as well as prevent the scattering of the radioactive materials upon cutting to the level as that in water cutting. Method: After igniting a gas cutting torch automatically, water spray by the local water sprayer is started by the actuation of a submerged pump, while a gas cutting manipulator is operated to cut the nuclear reactor pressure vessel. In this way, cutting exhaust gases resulted from the gas cutting torch are water-washed by the spray from the local water sprayer and falls within the nuclear rector pressure vessel in the form of water streams or droplets along the inner wall surface of the pressure vessel. Further, water is fed again to the local water sprayer by the submerged pump. (Kawakami, Y.)

Metal Transfer and Build-up in Friction and Cutting aims to systematize our knowledge of the metal build-up, to describe some of the investigations past and present carried out in SFTI (Tomsk), and to make an effort to explain a number of the phenomena in cutting, scratching, and sliding from the point of view of metal transfer theory. The book opens with a chapter on the temperature of the rubbing interface of two solids. This temperature is needed in order to elucidate the nature of the formation of a build-up in scratching, cutting, and sliding. Separate chapters follow on the seizure phen

A method and apparatus for diamond wire cutting of metal structures, such as nuclear reactor vessels, is provided. A diamond wire saw having a plurality of diamond beads with beveled or chamfered edges is provided for sawing into the walls of the metal structure. The diamond wire is guided by a plurality of support structures allowing for a multitude of different cuts. The diamond wire is cleaned and cooled by CO.sub.2 during the cutting process to prevent breakage of the wire and provide efficient cutting. Concrete can be provided within the metal structure to enhance cutting efficiency and reduce airborne contaminants. The invention can be remotely controlled to reduce exposure of workers to radioactivity and other hazards.

The aim of our research is to study respiratory and dermatologic diseases (irritative and allergic) in a cohort of workers exposed to vegetal esters based metalcutting fluids of the latest generation. A cohort of 81 workers (mean age 34.5 years, seniority 17.4 years), with mean exposure to vegetal esters based metalcutting fluids of 2.8 years, has been subjected to clinical evaluations. The investigation did not reveal any disease or disorder of the respiratory system, any folluculitis or any allergic contact dermatitis caused by sensitization to vegetal esters based metalcutting fluids. On the contrary we documented 5 cases of irritant contact dermatitis, even if favored by an improper use of protection devices. According to early results, the introduction of vegetal esters based metalcutting fluids seems to reduce the risk to the worker's health. A longitudinal surveillance is still needed to confirm that even in the medium and long-term sensitizations will not occur.

Metalcutting is one of the most common metal shaping processes. Specified geometrical and surface properties are obtained by break-up of the material removed by the cutting edge into a chip. The chip formation is associated with a large strain, high strain rate and a locally high temperature due to adiabatic heating which make the modelling of cutting processes difficult. This study compares a physically based plasticity model and the Johnson–Cook model. The latter is commonly used for high strain rate applications. Both material models are implemented into the finite element software MSC.Marc and compared with cutting experiments. The deformation behaviour of SANMAC 316L stainless steel during an orthogonal cutting process is studied

When discontinuous microcracks form on the shear plane they weld and reform as strain proceeds, thus joining the transport of dislocations in accounting for the total slip of the shear plane. In the presence of a contaminant, such as CCl4 vapour at a low cutting speed, the rewelding of microcracks decreases, resulting in ...

Chip formation in metalcutting is associated with large strains and high strain rates, concentrated locally to deformation zones in front of the tool and beneath the cutting edge. Furthermore, dissipative plastic work and friction work generate high local temperatures. These phenomena together with numerical complications make modelling of metalcutting difficult. Material models, which are crucial in metalcutting simulations, are usually calibrated based on data from material testing. Nevertheless, the magnitude of strains and strain rates involved in metalcutting are several orders higher than those generated from conventional material testing. A highly desirable feature is therefore a material model that can be extrapolated outside the calibration range. In this study, two variants of a flow stress model based on dislocation density and vacancy concentration are used to simulate orthogonal metalcutting of AISI 316L stainless steel. It is found that the addition of phonon drag improves the results somewhat but the addition of this phenomenon still does not make it possible to extrapolate the constitutive model reliably outside its calibration range. (paper)

Catalytic cutting by transition-metal (TM) particles is a promising method for the synthesizing of high-quality graphene quantum dots and nanoribbons with smooth edges. Experimentally, it is observed that the cutting always results in channels with zigzag (ZZ) or armchair (AC) edges. However, the driving force that is responsible for such a cutting behavior remains a puzzle. Here, by calculating the interfacial formation energies of the TM-graphene edges with ab initio method, we show that the surface of a catalyst particle tends to be aligned along either AC or ZZ direction of the graphene lattice, and thus the cutting of graphene is guided as such. The different cutting behaviors of various catalysts are well-explained based on the competition between TM-passivated graphene edges and the etching-agent-terminated ones. Furthermore, the kinetics of graphene catalytic cutting along ZZ and AC directions, respectively, are explored at the atomic level.

Tool produces slits of 0.0305 mm widths in materials up to RC 50 hardness, minimizes material waste and improves precision. Device may be used for general metalcutting and for producing simulated cracks in metal samples used in fatigue tests.

One of the most complicated steps in the demolition of nuclear power plants is the disassembly of radiologically burdened large components. Most of this work must be performed remotely and under a cover of water. Moreover, dimensions, structures, and locations pose problems. Various techniques of disassembly are available which have specific pros and cons. Thermal cutting techniques, i.e. plasma fusion cutting, contact arc metalcutting (CAMC), and contact arc metal grinding (CAMG), can be used with comparatively simple handling systems even for large material thicknesses and complex geometries. These thermal cutting techniques have been advanced considerably at the Institute for Materials Technology of the University of Hanover in recent years. In plasma fusion cutting, the workpiece is molten, partly evaporated, and the melt is blown out of the kerf by the gas jet. CAMC and CAMG are based on the thermal abrasion of electrically conducting materials under water by means of repeated non-steady short-circuit high-current arcs resulting from contacts between the electrode and the workpiece. Unlike plasma or laser beam cutting, hollow structures and sandwich structures pose no problems. The performance capability of plasma fusion cutting and contact arc metalcutting has been demonstrated impressively in the disassembly of reactor internals of the Karlsruhe multi-purpose research reactor (MZFR). (orig.)

Particulate metal matrix composites (MMCs) are known for their low weight and their high wear resistance, but also for the difficulties encountered during their machining. New aluminium MMCs containing with both soft lubricating graphite particles and hard particles (silicon carbide or alumina) with improved machinability were developed. This study investigates the drilling of these composites as compared to non-reinforced aluminium. The microstructure of chip, the cutting forces, the shear angles and the friction at tool-chip interface are used to compare the machinability of these composites. It was found that, during drilling of this new family of composites, the feed rate, and the nature of reinforcing particles govern the cutting forces. The mathematical models established by previous researchers for predicting the cutting forces when drilling metals were validated for these composites. The reinforcing particles within the composite help for chip segmentation, making the composite more brittle and easy to shear during the cutting process. (author)

The potential of carbon nanotube reinforcement of metallic binders for the improvement of quality and efficiency of diamond cutting wheels is studied. The effect of multi-walled carbon nanotube (MWCNT) reinforcement on the mechanical properties i.e. hardness, Young modulus, strength and deformation...... of grain size of the structural constituents of the binder, what in turn leads to the improved simultaneously hardness, Young modulus, plastic extension, bending strength and performances of the metallic binders. Comparing service properties of diamond end-cutting drill bits with and without MWCNT one...

Design Principles of Metal-Cutting Machine Tools discusses the fundamentals aspects of machine tool design. The book covers the design consideration of metal-cutting machine, such as static and dynamic stiffness, operational speeds, gearboxes, manual, and automatic control. The text first details the data calculation and the general requirements of the machine tool. Next, the book discusses the design principles, which include stiffness and rigidity of the separate constructional elements and their combined behavior under load, as well as electrical, mechanical, and hydraulic drives for the op

Paper describes possible procedures to cut contaminated large-size components in the course of the NPP dismantling, namely: the plasma arc cutting, the contact-arc-metal-cutting (CAMC), and the contact-arc metal grinding (CAMG). These techniques are usable when high thickness and sophisticated geometry of components, in this connection they are realized by relatively simple control systems. One considers application of some of the listed procedures (plasma arc cutting, contact-arc-metal-cutting) when dismantling the Karlsruhe multipurpose research reactor [ru

High-speed cutting burrs often throw minute particles of metal, bone, and soft tissue in the air during removal or revision of fracture fixation. A simple technique using lap sponges, water-soluble lubricant, and a smoke evacuator and shield can nearly eliminate soft-tissue contamination.

In this paper, the effects of the cutting speed in metallic glass grinding were investigated in dry conditions. The results showed that grinding forces decrease as grinding energy increase with the increasing cutting speeds. The present investigations on ground surface and grinding chips morphologies -shows that material removal and surface formation of the BMG are mainly due to the ductile chip deformation and ploughing as well as brittle fracture of some particles from the edges of the tracks. The roughness values obtained with the Cubic Boron Nitride wheels are acceptable for the grinding operation.

A 2-D finite-element-model for simulation of the chip formation process in metalcutting is presented. In order to consider the reciprocal interaction between mechanical and thermal loads during cutting a coupled-filed finite-element-analysis is carried out. The complex flow behavior of workpiece material which depends on local strain, strain rate and temperature is described by a thermo-viscoplastic workpiece model. The different frictional behavior in sticking and sliding regions is expressed by a nonlinear stress relationship between normal and frictional stresses at the tool-chip interface. To analyze the large deformation in the cutting zone more accurately a new technique of dynamic remeshing is developed. As the employed general purpose FEM-software Ansys does not support this feature, an additional preprocessor is developed and integrated into the program. With the aid of this remeshing technique the chip formation process can be simulated more closely to reality, i. e. the modeled tool is not assumed to be ideal sharp, but possesses nose radius and chip breaker. Simulations are carried out for conventional cutting conditions and the effects of cutting conditions, tool geometry and wear progress are examined. Furthermore, the segmented chip formation process during high speed cutting and/or during machining of hardened steel is also analyzed

During the preparatory dismantling activities of Caorso's Nuclear Power Plant (NPP), an experimental campaign using plasma and oxyacetylene metalcutting processes has been performed and applied to plates and tubes exposed to the coolant steam of the reactor. The plant (Boiling Water Reactor, 870 MWe) was designed and built in the 70's, and it was fully operating by 1981 to 1986 being shut down after 1987 Italy's poll that abrogated nuclear power based on U235 fission. The campaign concerns no activated materials, even if the analyses have been performed of by use contaminated components under the free release level, not yet taking into account radioactivity. In this paper, the parameters related to inhalable aerosol, solid and volatile residuals production have been, studied during hot processes which applies the same characteristics of the cutting in field for the dismantling programs of Caorso NPP. The technical parameters such as cutting time and cutting rate vs. pipe diameter/thickness/schedule or plate thickness for ferritic alloys and the emissions composition coming from the sectioning are also reported. The results underline the sort of trouble that can emerge in the cutting processes, in particular focusing on the effects comparison between the two cutting processes and the chemical composition of powders captured by filtering the gaseous emission. Some preliminary considerations on methodology to be used during the dismantling have been presented. (authors)

In this report, we analytically predict and examine stresses in tool tips used in high speed orthogonal machining operations. Specifically, one analysis was compared to an existing experimental measurement of stresses in a sapphire tool tip cutting 1020 steel at slow speeds. In addition, two analyses were done of a carbide tool tip in a machining process at higher cutting speeds, in order to compare to experimental results produced as part of this study. The metal being cut was simulated using a Sandia developed damage plasticity material model, which allowed the cutting to occur analytically without prespecifying the line of cutting/failure. The latter analyses incorporated temperature effects on the tool tip. Calculated tool forces and peak stresses matched experimental data to within 20%. Stress contours generally agreed between analysis and experiment. This work could be extended to investigate/predict failures in the tool tip, which would be of great interest to machining shops in understanding how to optimize cost/retooling time.

Presented are the data of comparative studies of the cutting surface, made by the electrodes of the ANR-2 type and by the coal electrode by the method of air-arc cutting. Absence of carbonization of cutting surface, minimum structural changes in metal and a considerably high productivity permit to recommend the ANR-2 and ANR-2M electrodes for separation metalcutting, weld root and defect area cut without further stripping by the grinding stone

The optimization problem for NC laser combined cutting of sheet metal parts was taken as the research object in this paper. The problem included two contents: combined packing optimization and combined cutting path optimization. In the problem of combined packing optimization, the method of “genetic algorithm + gravity center NFP + geometric transformation” was used to optimize the packing of sheet metal parts. In the problem of combined cutting path optimization, the mathematical model of cutting path optimization was established based on the parts cutting constraint rules of internal contour priority and cross cutting. The model played an important role in the optimization calculation of NC laser combined cutting.

The microstructural evolution following metalcutting was investigated within the metal chips of Ti-6Al-4V. Metalcutting was used to impose a high strain rate on the order of approx.10(exp 5)/s within the primary shear zone as the metal was removed from the workpiece. The initial microstructure of the parent material (PM) was composed of a bi-modal microstructure with coarse prior grains and equiaxed primary located at the boundaries. After metalcutting, the microstructure of the metal chips showed coarsening of the equiaxed primary grains and lamellar. These metallographic findings suggest that the metal chips experienced high temperatures which remained below the transus temperature.

Machine tool chatter is an unfavorable phenomenon during metalcutting, which results in heavy vibration of cutting tool. With increase in depth of cut the cutting regime changes from chatter- free cutting to one with chatter. In this paper, we propose the use of permutation entropy (PE), a conceptually simple and computationally fast measure to detect the onset of chatter from the time series generated using laser speckle pattern recorded using Charge Couple Device (CCD) camera. Laser speckle is an interference pattern produced by light reflected or scattered from different parts of the illuminated surface. It is the superposition of many wave fronts with random phases, scattered from different parts of the rough surface. If a speckle pattern is produced by coherent light incident on a rough surface, then surely the speckle pattern, or at least the statistics of the speckle pattern, must depend upon the detailed surface properties. Therefore we propose PE as an ideal measure, which can efficiently distinguish regular and complex nature of any signal, to extract information about the roughness of the reflecting surface. In the present study two work pieces, one taper cut and one step cut are machined to form cylindrical pieces, by continuously varying the depth of cut. As the depth of cut increases the surface finish is expected to deteriorate, mainly due to the onset of chatter vibrations. To analyze the surface texture characteristics, the speckle pattern is obtained by illuminating this curved surface using a collimated laser beam (5mW Diode Laser at 676nm wavelength.). The laser beam is made to incident obliquely to the curved surface of the work piece, and the speckle pattern is recorded using a CCD camera. The beam is scanned along the axis of the work-piece and the speckle pattern is recorded at different regions at constant intervals. A time series is generated from the speckle data and analyzed using PE. Permutation entropy is a complexity measure suitable

Full Text Available Due to the environmental and health issues, there is an enormous requirement for developing the novel cutting fluids (CFs. The vegetable based cutting fluid (VBCFs doesn’t affect the environment, diminish the harmful effects to the operator and also enhance the machining performances such as surface roughness, tool life, minimum vibration and cutting forces. In this work, the performances of four different VBCFs like palm, coconut, sunflower, soya bean oils, and a commercial type of CFs were considered to analyze the influence of cutting fluids while measuring the cutting force and vibration signatures during milling of 7075–T6 hybrid aluminium metal matrix composite with carbide insert tool. The experiments were conducted in CNC L-MILL 55 vertical machining center, with milling tool dynamometer to measure the cutting force and a tri-axial accelerometer to measure the vibration signals. The flow rate of the VBCFs were maintained at a constant rate and the results were compared with a commercial cutting fluid. The obtained result shows that palm oil suits better than the other vegetable based cutting fluids in terms of minimum cutting force requirement and minimum vibration. Also, the experimental result shows that the cutting fluid was one of the important parameter needs to be considered which influences the cutting force and vibration signals.

A laser cutting assembly has been made which allows laser beam to be focused on a job submerged under water, even though the laser head remains outside water. Under water cutting will be very useful for cutting of radioactive materials inside pool or storage bay. This can also be used for reactive materials like uranium etc which otherwise are difficult to cut in open atmosphere as they catch fire. The effect of cutting parameters on the cut quality and also comparison between under-water cutting and open air-cutting is discussed. (author). 2 refs., 1 tab

The article highlights the issues of determining the stability of the cutting process by a multipoint cutting tool equipped with cutting ceramics. There were some recommendations offered on the choice of parameters of replaceable cutting ceramic plates for milling based of the conducted researches. Ceramic plates for milling are proposed to be selected on the basis of value of their electrical volume resistivity.

The decommissioning of nuclear facilities requires cutting techniques for metallic structures which must be technically safe and easy to handle remotely controlled. The most effective protection of the staff can be obtained when the work is carried out under water. Thus the personnel's exposure to ionizing radiation can be kept to a minimum. Under water plasma arc cutting offers some specific advantages for these cutting tasks. However the necessary plasma arc cutting and handling equipment to dismantle complex structures remotely controlled is not yet available. A handling system for under water plasma arc cutting of metallic components is under development in the Institut fur Werkstoffkunde, University of Hanover, Germany. (Author)

Full Text Available Cutting forces are classified among the most important technological parameters in machining process. Cutting forces are the background for the evaluation of the necessary machining power, as well as for dimensioning of the tools. Cutting forces are also having a major influence on the deformation of the work piece machined, its dimensional accuracy, and machining system stability.

Beam manipulation by metallic nanoslit arrays with perpendicular cuts inside the slits was investigated numerically. The simulated results performed by the finite element method (FEM) show that perpendicular cuts with different heights can modulate phase retardation of the transmitted light through the slits. With the proper distribution of cut height, a focused beam is achieved in our metallic nanostructure with four-time amplitude at the focus point and half focal length compared to a slit array without cuts inside. By using asymmetric distribution of height amplitude, a beam deflection around 6° can also be realized in our design

The microstructural evolution following metalcutting was investigated within metal chips of Ti-6Al-4V. Metalcutting was used to impose a high strain rate on the order of approx.10(exp 5)/s within the primary shear zone as the metal was removed from the workpiece. The initial microstructure of the parent material (PM) was composed of a bi-modal microstructure with coarse prior beta grains and equiaxed primary alpha located at the boundaries. After metalcutting, the microstructure of the metal chips showed coarsening of the equiaxed primary alpha grains and beta lamellar. These metallographic findings suggest that the metal chips experienced high temperatures which remained below the beta transus temperature.

Laser cutting has been investigated for a number of aluminum–synthetic laminates, newly developed materials for the aeronautic and automotive industry. The materials consist of alternating aluminum and synthetic layers. It is shown that these materials can be cut at the same speed as homogeneous

and Delta Steel Companies show that the level of technology transfer from ... Armor 35' was used to measure the total cutting length a tool will cut ... surface roughness parameter has been the focus of experimental investigations. The surface profile parameters have only been theoretically modelled by. [11, 12].The need to ...

Highlights: • A nanoscale chip with a shear plane of 135° is extruded by the tool. • Tangential force and normal force increase with increasing tool nose radius. • Resistance factor increases with increasing cutting depth and temperature. - Abstract: The effects of cutting depth, tool nose radius, and temperature on the cutting mechanism and mechanics of amorphous NiAl workpieces are studied using molecular dynamics simulations based on the second-moment approximation of the many-body tight-binding potential. These effects are investigated in terms of atomic trajectories and flow field, shear strain, cutting force, resistance factor, cutting ratio, and pile-up characteristics. The simulation results show that a nanoscale chip with a shear plane of 135° is extruded by the tool from a workpiece surface during the cutting process. The workpiece atoms underneath the tool flow upward due to the adhesion force and elastic recovery. The required tangential force and normal force increase with increasing cutting depth and tool nose radius; both forces also increase with decreasing temperature. The resistance factor increases with increasing cutting depth and temperature, and decreases with increasing tool nose radius.

Full Text Available In this paper an effect of using of minimal quantity lubrication (MQL technique in turning operations is presented. Experimental research was performed on carbon steel C45E. Technological parameters: depth of cut, feed rate and cutting speed were adjusted to semi-machining and roughing. Higher values ​​of feed and cutting speed were used, than recommended from literature and different types of cooling and lubrication in turning conditions were applied. As a conventional procedure and technology, lubrication with flooding was applied. As special lubrication the MQL technique was used. During research, monitoring of the cutting force, chip shape, tool wear and surface roughness was performed. Relations between parameters, material machinability and economy of process were analyzed.

SA401M2 installation for semiautomatic air-plasma cutting is described. Results of metallographic investigations and gas analysis of cutting edges of low-carbon steel are presented. It is shown that SA401M2 installation provides separation of metal up to 6 mm thickness at 45-85A current when nozzle is resting on a sample

This study aimed to compare growth performance and heavy metal (HM) accumulation at different cutting positions of Salix species grown in multi-metal culture. Three Salix species stems cut at different positions (apical to basal) were grown hydroponically for four weeks. The plants were then treated for three weeks with 0, 5, 10, and 20 μM Cd, Cu, Pb, and Zn, resulting in total metal concentrations of 0, 20, 40, and 80 μM. The growth parameters and HM content in shoots and initial cutting were measured. Results showed that, compared with S. fragilis, S. matsudana grew more poorly in uncontaminated condition but grew better and accumulated lower metal in shoots under mixed HM treatment. In addition, cuttings from apical parent stem position exhibited poorer growth performance before and after treatment, as well as greater metal content in shoots than base parts under the HM treatment. These results suggest that S. matsudana may undergo a special mechanism to hinder metals in the initial cutting, thus mitigating growth damage. The apical portion also showed poor resistance against the invasion of mixed HMs because of the immature structure. Therefore, in the selection of phytoremediation plants, metal accumulation ability is not proportional to growth performance.

The recent 1μm-laser cutting market is dominated by fiber and disk lasers due to their excellent beam quality of below 4mm*mrad. Teradiode's 4kW direct diode laser source achieves similar beam quality while having a different beam shape and shorter wavelengths which are known for higher absorption rates at the inclined front of the cutting keyhole. Research projects, such as the HALO Project, have additionally shown that polarized radiation and beams with shapes different from the typical LG00 lead to improved cut quality for ferrous and non-ferrous metals. [1] Diode laser have the inherent property of not being sensitive to back reflection which brings advantages in cutting high-reflective materials. The II-VI HIGHYAG laser cutting head BIMO-FSC offers the unique feature of machine controlled and continuous adjustment of both the focus diameter and the focus position. This feature is proven to be beneficial for cutting and piercing with high speed and small hole diameters. In addition, the optics are designed for lowest focus shift. As a leading laser processing head manufacturer, II-VI HIGHYAG qualified its BIMO-FSC MZ (M=magnification, Z=focus position) cutting head for Teradiode's 4kW direct diode laser source to offer a cutting-edge solution for highpower laser cutting. Combining the magnification ability of the cutting head with this laser source, customers experience strong advantages in cuttingmetals in broad thickness ranges. Thicknesses up to 25mm mild steel can easily be cut with excellent edge quality. Furthermore, a new optical setup equivalent to an axicon with a variable axicon angle is demonstrated which generates variable sized ring spots. The setup provides new degrees of freedom to tailor the energy distribution for even higher productivity and quality.

Full Text Available Hybrid metal matrix composites are of great interest for researchers in recent years, because of their attractive superior properties over traditional materials and single reinforced composites. The machinabilty of hybrid composites becomes vital for manufacturing industries. The need to study the influence of process parameters on the cutting forces in turning such hybrid composite under dry environment is essentially required. In the present study, the influence of machining parameters, e.g. cutting speed, feed and depth of cut on the cutting force components, namely feed force (Ff, cutting force (Fc, and radial force (Fd has been investigated. Investigations were performed on 0, 2, 4, 6 and 8 wt% Silicon carbide (SiC and rice husk ash (RHA reinforced composite specimens. A comparison was made between the reinforced and unreinforced composites. The results proved that all the cutting force components decrease with the increase in the weight percentage of the reinforcement: this was probably due to the dislocation densities generated from the thermal mismatch between the reinforcement and the matrix. Experimental evidence also showed that built-up edge (BUE is formed during machining of low percentage reinforced composites at high speed and high depth of cut. The formation of BUE was captured by SEM, therefore confirming the result. The decrease of cutting force components with lower cutting speed and higher feed and depth of cut was also highlighted. The related mechanisms are explained and presented.

In order to advance understanding of the burr formation process, a series of finite element models are introduced. First a finite element model of the burr formation of two-dimensional orthogonal cutting is introduced and validated with experimental observations. A detailed and thorough examination of the drilling burr forming process is undertaken. This information is then used in the construction of an analytical model and, leads to development of a three-dimensional finite element mode...

Full Text Available Abstract. Objectives In the article, problems in the optimising of machining operations, which provide end-unit production of the required quality with a minimum processing cost, are addressed. Methods Increasing the effectiveness of experimental research was achieved through the use of mathematical methods for planning experiments for optimising metalcutting tasks. The minimal processing cost model, in which the objective function is polynomial, is adopted as a criterion for the selection of optimal parameters. Results Polynomial models of the influence of angles φ, α, γ on the torque applied when cutting threads in various steels are constructed. Optimum values of the geometrical tool parameters were obtained using the criterion of minimum cutting forces during processing. The high stability of tools having optimal geometric parameters is determined. It is shown that the use of experimental planning methods allows the optimisation of cutting parameters. In optimising solutions to metalcutting problems, it is found to be expedient to use multifactor experimental planning methods and to select the cutting force as the optimisation parameter when determining tool geometry. Conclusion The joint use of geometric programming and experiment planning methods in order to optimise the parameters of cutting significantly increases the efficiency of technological metal processing approaches.

Full Text Available The paper is aimed at studying the composition and properties of the wastes generated during metal waterjet cutting and assessing the possibility of their use in building materials production. The essence of waterjet cutting process, waste generation mechanism, waste accumulation volumes at enterprises are described. The composition and properties of the used abradant – garnet sand is given and the features of its destruction during cutting are revealed. Waterjet cutting wastes are comprehensively studies: average and bulk density, granulometric composition, chemical composition are determined, various fractions are studied with an electronic microscope. It is revealed that during cutting abradant particles are destroyed, a large amount of dust fraction emerges with the particles of cutmetal mixed into it. The metal waterjet cutting wastes are found to be very small, practically monofractive, heavy sands with a high content of dust fraction, which chemical composition is dominated by oxides of iron, silicon and aluminum. This characteristic of the wastes has allowed us to outline possible ways of how to use them: in ceramic items production as thinning agents and fluxing agents, in Portland cement production as a correcting iron-containing agent, as a mortar filler, including special mortars, as a building materials volumetric staining pigment, etc.

A device was developed for the production of U 3 O 8 from cuttings of depleted uranium metal or of uranium metal waste whose surface area is sufficiently large for combustion. The waste may contain organic impurities or other metals. The purity of the U 3 O 8 thus obtained is about 98%. Tests gave evidence that the combustion facility meets all requirements set forth by hygienic and ecological regulations. (Z.M.). 1 fig

A model of the repetitively pulsed gas-jet laser cutting of thick metals in an oxidising gas is developed. It is shown that the optimal choice of the time-dependent (radiation) and beam-focusing parameters will make it possible to increase the average cutting rate by a factor of 1.5 - 1.8. (interaction of laser radiation with matter. laser plasma)

The changes in today's metal working technology are driven by increasing cutting speeds, heavy/hard machining and an enormous amount by changes in work piece materials. These applications are asking for more tailor made cutting tool solutions. Together with the well established multi component coating technology a new approach of composite coatings is giving solutions for the tough demands of the cutting tool market. In this paper is presented composite coatings of AI 2 O 3 /ZrO-2/TiO x made by CVD. The coating is like high performance oxide ceramics for cutting applications. The coating is used in combination with MT CVD coatings and different carbide substrates. The CVD coating has optimum stress for cutting applications, low friction and very high thermal isolation. The outstanding performance of this coating is demonstrated in different applications. (author)

Decommissioning of radioactively contaminated sites has the potential for creating radioactive and other potentially toxic aerosols. We describe an experimental system to collect and characterize aerosols from metalcutting activities typical of those used in decommissioning of nuclear facilities. A special enclosure was designed for the experiment and consisted of a 5.1 cm x 10.2 cm stud frame with double walls of flame retardant polyethylene film. Large plexiglass windows allowed the cutting operations to be directed and filmed. Ventilation was 8500 liters/minute (300 CFM) exhausted through HEPA filters. Seven cutting techniques were evaluated: pipe cutter, reciprocating saw, band saw, chop saw, oxy-acetylene torch, electric arc cut rod and plasma torch. Two grinding tools were also evaluated. Materials cut were 5.1 cm, 7.6 cm and 10.2 cm diameter schedule 40, 80 and 180 type 304L stainless steel pipe

Pollution related activities in addition to handling cost of conventional cutting fluid application in metalcutting industry has generated a lot of concern over time. The desire for a green machining environment which will preserve the environment through reduction or elimination of machining related pollution, reduction in oil consumption and safety of the machine operators without compromising an efficient machining process led to search for alternatives to conventional cutting fluid. Amongst the alternatives of dry machining, cryogenic cooling, high pressure cooling, near dry or minimum quantity lubrication (MQL), MQL have shown remarkable performance in terms of cost, machining output, safety of environment and machine operators. However, the MQL under aggressive machining or very high speed machining pose certain restriction as the lubrication media cannot perform efficiently at elevated temperature. In compensating for the shortcomings of MQL technique, high thermal conductivity nanoparticles are introduced in cutting fluids for use in the MQL lubrication process. They have indicated enhanced performance of machining process and significant reduction of loads on the environment. The present work is aimed at evaluating the application and performance of nanofluid in metalcutting process through MQL lubrication technique highlighting their impacts and prospects as lubrication strategy in metalcutting process for sustainable green manufacturing. Enhanced performance of vegetable oil based nanofluids over mineral oil-based nanofluids have been reported and thus highlighted.

In this work, molecular dynamics simulations are performed to investigate the influence of material properties on the nanometric cutting of single crystal copper and aluminum with a diamond cutting tool. The atomic interactions in the two metallic materials are modeled by two sets of embedded atom method (EAM) potential parameters. Simulation results show that although the plastic deformation of the two materials is achieved by dislocation activities, the deformation behavior and related physical phenomena, such as the machining forces, machined surface quality, and chip morphology, are significantly different for different materials. Furthermore, the influence of material properties on the nanometric cutting has a strong dependence on the operating temperature.

Holes 20A in diameter and fine lines 20A wide can be cut in the metal-β-aluminas using the 10A electron beam of the Vacuum Generators, HB5 scanning transmission electron microscope. The minimum current density required for cutting was 10 3 amp/cm 2 . Electron energies of 40, 60, 80, and 100 keV were used. In the case reported here, uniform 20A holes and lines were cut through self-supporting 1000A thick slabs of sodium-β-alumina to provide very high electron contrast. Once cut, the β-aluminas are stable and will tolerate exposure to air without degradation of the electron cut patterns. They may be used directly as masks (eg. for ion implantation). They could probably be cut on the substrate with no damage to the underlying material. These specimens, once cut, can be removed from the microscope and stored, then returned for further cutting or viewing. 6 references, 3 figures

In metalcutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production; therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature measurement employing both a K-type thermocouple and an infrared radiation (IR) pyrometer to measure the tool-chip interface temperature. Due to the complexity of the machining processes, the integration of different measuring techniques was necessary in order to obtain consistent temperature data. The thermal analysis results were compared via the ANSYS finite element method. Experiments were carried out in dry machining using workpiece material of AISI 4140 alloy steel that was heat treated by an induction process to a hardness of 50 HRC. A PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. The results showed that with increasing cutting speed, feed rate and depth of cut, the tool temperature increased; the cutting speed was found to be the most effective parameter in assessing the temperature rise. The heat distribution of the cutting tool, tool-chip interface and workpiece provided effective and useful data for the optimization of selected cutting parameters during orthogonal machining.

Full Text Available In metalcutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production; therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature measurement employing both a K-type thermocouple and an infrared radiation (IR pyrometer to measure the tool-chip interface temperature. Due to the complexity of the machining processes, the integration of different measuring techniques was necessary in order to obtain consistent temperature data. The thermal analysis results were compared via the ANSYS finite element method. Experiments were carried out in dry machining using workpiece material of AISI 4140 alloy steel that was heat treated by an induction process to a hardness of 50 HRC. A PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. The results showed that with increasing cutting speed, feed rate and depth of cut, the tool temperature increased; the cutting speed was found to be the most effective parameter in assessing the temperature rise. The heat distribution of the cutting tool, tool-chip interface and workpiece provided effective and useful data for the optimization of selected cutting parameters during orthogonal machining.

In metalcutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production; therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature measurement employing both a K-type thermocouple and an infrared radiation (IR) pyrometer to measure the tool-chip interface temperature. Due to the complexity of the machining processes, the integration of different measuring techniques was necessary in order to obtain consistent temperature data. The thermal analysis results were compared via the ANSYS finite element method. Experiments were carried out in dry machining using workpiece material of AISI 4140 alloy steel that was heat treated by an induction process to a hardness of 50 HRC. A PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. The results showed that with increasing cutting speed, feed rate and depth of cut, the tool temperature increased; the cutting speed was found to be the most effective parameter in assessing the temperature rise. The heat distribution of the cutting tool, tool-chip interface and workpiece provided effective and useful data for the optimization of selected cutting parameters during orthogonal machining. PMID:25587976

Laser cutting performances for thick carbon steel and stainless steel specimens up to 300 mm in thickness were studied to dismantle large steel objects. The cutting performances were summarized based on the assist gas flow rate and the front kerf width, and the range for appropriate cutting conditions was shown. Gas pressure in the kerf region required for molten metal removal was estimated from the pressure loss on the kerf surface, which depended on the gas flow rate and the kerf width. The relation to keep sufficient gas pressure in the kerf well corresponded to the experimental relations for appropriate cutting. Drag force to the molten metal on the kerf surface was also estimated, which varied by the structures and materials. The behaviors such as cavity formation and its expansion in the kerf region at the unsuccessful cutting trials were well explained. The results are informative for the development of the laser cutting technology applied to the thick steel specimen for the nuclear decommissioning. (author)

Dismantling radiologically burdened large components is among the most complex and difficult jobs in the demolition of nuclear installations. The technologies used and their safe operation play a key role in demolition. Dismantling highly activated components as a rule requires shielding by water. As a consequence, the techniques employed must be designed for use under water. A variety of technologies are available for these applications. One established mechanical cutting method is water abrasive suspension jet cutting (WASS). Because of the small cutting nozzle employed, this highly flexible cutting technique can be used nearly anywhere together with different guiding systems. In the course of disassembly under water of the MZFR, plasma cutting has been found to be a reliable and efficient technique for remote operation. Contact arc metalcutting is a thermal cutting technique allowing all electrically conducting materials, including those with claddings, to be cut nearly irrespective of their component geometries. The methods, technology, possible uses, and practical operation of contact arc metalcutting in the demolition of the MZFR are covered in this article. (orig.)

At the present time, only 5 percent of the short-run metal-cutting machining in the United States is done by numerically controlled machined tools, but within the next decade it is expected to increase by 50 percent. Numerically controlled machines use taped data which is changed into instructions and directs the machine to do certain steps…

For best results and the highest speed of cutting sheet metal by high power lasers, the numerical aperture of the focussed beam must be properly matched to the material thickness. To alleviate the need for frequent changes of fixed-focal-length lenses a zoom lens system which allows fast and

To cut soft materials such as biological tissues with minimal damage and reduced positional error is highly desired in medical surgery and biomechanics. After years of natural selection and evolution, mosquitoes have acquired the ability to insert their proboscises into human skin with astonishingly tiny forces. This can be associated with the unique structure of their proboscises, with micro/nano sawteeth, and the distinctive insertion manner: high frequency reciprocating saw cutting. Inspired by these, this communication describes the successful implantation of metal oxide particles onto molybdenum wire surfaces through a sol-calcination process, to form a biomimetic sawblade with a high density of micro/nano saw teeth, where the acidification is essential in terms of generating active anchoring sites on the wire. When used as a sawblade in conjunction with reciprocating action to cut the viscoelastic gel, both the cut-in force and cut-in displacement could be decreased substantially. The cutting speed and frequency of reciprocating action are important operating parameters influencing cut-in force.

Railway transportation is an important transportation mode. However, railway transportation causes heavy metal pollution in surrounding soils. Heavy metal pollution has a serious negative impact on the natural environment, including a decrease of enzyme activities in soil and degradation of sensitive ecosystems. Some studies investigated the heavy metal pollution at railway stations or certain transportation hubs. However, the pollution accumulated in artificial cut slope soil all along the rails is still questioned. The interest on non-point source pollution from railways is increasing in an effort to protect the soil quality along the line. In this study, we studied spatial distributions of heavy metals and five enzyme activities, i.e., urease (UA), saccharase (SAC), protease (PRO), catalase (CAT), and polyphenol oxidase (POA) in the soil, and the correlation among them beside three different railways in Sichuan Province, China, as well. Soil samples were respectively collected from 5, 10, 25, 50, 100, and 150 m away from the rails (depth of 0-8 cm). Results showed that Mn, Cd, Cu, and Zn were influenced by railway transportation in different degrees while Pb was not. Heavy metal pollution was due to the abrasion of the gravel bed as well as the tracks and freight transportation which caused more heavy metal pollution than passenger transportation. Enzymatic activities were significantly negatively correlated with heavy metals in soils, especially Zn and Cu. Finally, it is proposed that combined use of PRO and POA activities could be an indicator of the heavy metal pollution in cut slope soils. The protective measures aimed at heavy metal pollution caused by railway transportation in cut slope soils are urgent.

The overall objective of this research project was to investigate the heavy metals environmental security control of resource utilization of shale gas' drilling cuttings. To achieve this objective, we got through theoretical calculation and testing, ultimately and preliminarily determine the content of heavy metals pollutants, and compared with related standards at domestically and abroad. The results indicated that using the second Fike's law, the theoretical model of the release amount of heavy metal can be made, and the groundwater environmental risk as main point compared with soil. This study can play a role of standard guidance on environmental security control of drilling cuttings resource utilization by the exploration and development of shale gas in our country.

This paper focuses on one aspect of occupational dioxin exposure that is novel and unexpected. Exposures in excess of the German threshold limit value of 50 pg international toxicity equivalent (I-TEQ)/m3 are very frequent, unpredictable, and sometimes very high--up to 6612 pg I-TEQ/m3--during thermal oxygen cutting at scrap metal and demolition sites. The same procedure involving virgin steel in steel trade and mass production of steel objects gave no such evidence, even though no final conclusions can be drawn because of the low number of samples analyzed. Low dioxin exposures during inert gas electric arc welding confirm previous literature findings, whereas soldering and thermal oxygen cutting in the presence of polyvinyl chloride give rise to concern. The consequences of occupational dioxin exposure were studied by analysis of the dioxin-blood concentration, the body burden, of men performing thermal oxygen cutting at scrap metal reclamation and demolition sites, in steel trade and producing plants as well as for industrial welders and white-collar workers. The results concerning body burdens are in excellent agreement with the dioxin exposure as characterized by dioxin air concentration in the workplace. The significant positive correlation between duration and frequency of performing thermal oxygen cutting at metal reclamation and demolition sites expressed in job-years and dioxin body burden speaks for the occupational origin of the observed overload after long times. The results reported here lead to consequences for occupational health, which are discussed and require immediate attention.

Cutting is a ubiquitous process in nature and man-made systems. Here we demonstrate that, based on morphological patterns observed in experiments, the friction behaviour of metalcutting exhibits a criticality with cutting speed as a tuned parameter. The corresponding stick-slip events can be described by a power law distribution. A dynamic thermo-mechanical model is developed to investigate how such a tuned criticality occurs. It is shown that, in terms of the linear stability analysis, stick-slip friction is due to the thermo-mechanical instability and dynamical interaction between shear dissipation and nonlinear friction. Moreover, there is a secondary transition from a criticality state to a limit cycle that is dominated by the inertia effect, which is similar to the frequency lock phenomenon in a forced Duffing oscillator. (paper)

This document contains the teacher and student texts and student workbook for a secondary-level course in shielded metal arc welding (SMAW) and carbon arc cutting that consists of units on the following topics: SMAW safety; SMAW equipment, applications, and techniques; hardfacing; and carbon arc cutting--air. The teacher edition includes the…

The design and use of equipment to perform work in radioactive environments is uniquely challenging. Some tasks require that the equipment be operated by a person wearing a plastic suit or full face respirator and donning several pairs of rubber gloves. Other applications may require that the equipment be remotely controlled. Other important, design considerations include material compatibility, mixed waste issues, tolerance to ionizing radiation, size constraints and weight capacities. As always, there is the ''We need it ASAP'' design criteria. This paper describes four applications where different types of metalcutting technologies were used to successfully perform tasks in radioactive environments. The technologies include a plasma cutting torch, a grinder with an abrasive disk, a hydraulic shear, and a high pressure abrasive water jet cutter

The effect of polarisation of a Gaussian beam on the radiation absorption during laser cutting of metals is investigated. A generalised formula is proposed for calculating the absorption coefficient, which describes the polarisation of three types (linear, elliptical, and circular), taking into account the fact that the beam may interact with a metal surface of an arbitrary shape. A comparison with the existing analogues (in the cases of linear and circular radiation polarisation) confirmed the advantage of employing the formula for the spatial description of the shape of the surface produced, which is highly important for processing (cutting, welding, drilling) of thick materials. The effect of laser radiation characteristics on the surface shape and cut depth in cutting stainless steel sheets is investigated numerically. It is shown for the first time that the cutting of materials by the TEM 00 beam is most efficient when the beam has elliptical polarisation directed along the direction of beam displacement and characterised by a specific axial ratio. (laser applications and other topics in quantum electronics)

The authors study the influence of cooling rate in high-temperature area for thermal cycle of high-cutting chrome-tungsten metal weld deposit on the processes of carbide phase merging and austenite grain growth for the purpose of providing high hardness of deposited metal (HRC 64-66). (paper)

This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils) and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils) were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination.

Full Text Available This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination.

Molten metal behaviors during the laser cutting of carbon steel and stainless steel specimens up to 300 mm in thickness were observed to dismantle large steel objects for the nuclear decommissioning, where attenuated process images from both steels were observed for detailed process analysis. Circular and rod-like molten metal structures were observed at the laser irradiated region depending on the assist gas flow conditions. Molten metal blow-off and flow processes were observed as cutting processes. The observations were explained by the aerodynamic interaction of the melted surface layer. The method is useful for the detailed observation of the molten metal behaviors, and the results are informative to understand and optimize the laser cutting process of very thick steel specimens. (author)

We report on a fragment of the quasicrystal-bearing CV3 carbonaceous chondrite Khatyrka recovered from fine-grained, clay-rich sediments in the Koryak Mountains, Chukotka (Russia). We show higher melting-point silicate glass cross-cutting lower melting-point Al-Cu-Fe alloys, as well as unambiguous evidence of a reduction-oxidation reaction history between Al-Cu-Fe alloys and silicate melt. The redox reactions involve reduction of FeO and SiO 2 to Fe and Fe-Si metal, and oxidation of metallic Al to Al 2 O 3 , occurring where silicate melt was in contact with Al-Cu-Fe alloys. In the reaction zone, there are metallic Fe and Fe-Si beads, aluminous spinel rinds on the Al-Cu-Fe alloys, and Al 2 O 3 enrichment in the silicate melt surrounding the alloys. From this and other evidence, we demonstrate that Khatyrka must have experienced at least two distinct events: first, an event as early as 4.564 Ga in which the first Al-Cu-Fe alloys formed; and, second, a more recent impact-induced shock in space that led to transformations of and reactions between the alloys and the meteorite matrix. The new evidence firmly establishes that the Al-Cu-Fe alloys (including quasicrystals) formed in outer space in a complex, multi-stage process.

Cubic boron nitride coatings are under development for a variety of applications but stabilization of the pure cBN form and adhesion of films deposited by PVD and ion-based methods has been difficult. An alternative method for depositing a composite cBN-TiN film has been developed for wear related applications. The coating is deposited in a two-stage process utilizing ESC (electrostatic spray coating) and CVI (chemical vapor infiltration). Fully dense films of cBN particles evenly dispersed in a continuous TiN matrix have been developed. Testing in metalcutting has shown an increase in tool life (turning - 4340 steel) of three to seven times, depending of machining parameters, in comparison with CVD deposited TiN films. (author)

We report the use of transition metal nanoparticles (Ni or Co) to longitudinally cut open multiwalled carbon nanotubes in order to create graphitic nanoribbons. The process consists of catalytic hydrogenation of carbon, in which the metal particles cut sp(2) hybridized carbon atoms along nanotubes that results in the liberation of hydrocarbon species. Observations reveal the presence of unzipped nanotubes that were cut by the nanoparticles. We also report the presence of partially open carbon nanotubes, which have been predicted to have novel magnetoresistance properties.(1) The nanoribbons produced are typically 15-40 nm wide and 100-500 nm long. This method offers an alternative approach for making graphene nanoribbons, compared to the chemical methods reported recently in the literature.

Used spent fuel baskets have been stored in the La Hague North-West concrete-lined pits until decommissioning. In 1998, COGEMA decided to retrieve, cut and condition these spent fuel baskets. This paper describes the experience gained, since the start up of this operation in 1999, discusses resulting dosimetry and waste produced, during retrieving and remotely cutting of LL activity large metallic structures. This process result in significantly lower exposures to workers in the D and D operations. In addition the work was carried out in an environmentally safe manner with reasonable financial costs.

A fully coupled (strong coupling) thermo-elasto-visco-plastic-damage constitutive equations based on the state variables under large plastic deformation developed for metal forming simulation are presented. The relevant numerical aspects concerning either the local integration scheme as well as the global resolution strategy are discussed. This model is implemented into ABAQUS/EXPLICIT using the Vumat user subroutine. Applications are made to the orthogonal metalcutting by chip formation and segmentation. The interaction between hardening plasticity, ductile damage and thermal effects are carefully analyzed. The numerical results obtained with this procedure based on the damage coupling are compared with those obtained with the classical procedure neglecting the damage effect

Heavy metal contamination in the artificial soils on the railway cut slopes may have great influence on the revegetation of the cut slopes. The purpose of this study was to assess the variation of heavy metal contamination levels with railway operation time and analyze their possible resources. A total of 100 soil samples from four cut slopes, which were affected by railway transportation for different years, were analyzed for metal pollution (Cd, Pb, Cr, Cu, Zn, Fe). The concentrations of Cd, Pb showed increasing trend with increasing operation time of railways, while such trend was not found in Cr, Cu, Zn, Fe. According to the soil quality standard of China, Cd was considered to have considerable contamination, while Pb has less, but Cr, Cu, Zn, Fe have none. Moreover, cadmium exhibited remarkably higher levels rather than those reported in other studies. Enrichment factors and ecological index showed that Cd and Pb showed a moderate enrichment and a considerable ecological risk in most of the soil samples. The results of descriptive statistic, principal component analysis, cluster analysis and correlation analysis were totally consistent with each other. Their results revealed that Cr, Cu, Zn and Fe had common origins, and they may come from natural resources. While Cd and Pb were significantly influenced by railway transportation, leaked cargos, fuel combustion, the use of lubricate oils and sleeper impregnation oils during railway transportation may be their main resources.

While stent restenosis and late thrombosis still occur even with drug-eluting-stents (DES), there remains a need to explore other strategies for preventing restenosis. Five hundred and twenty-one patients were randomized: 260 to cutting-balloon angioplasty (CBA) before bare-metal stent (CBA-BMS) and 261 to balloon-angioplasty (BA) before BMS (BA-BMS). Intravascular ultrasound (IVUS)-guided procedures were performed in 279 (54%) patients and angiographic guidance was used in the remainder. Minimal lumen diameter was significantly greater in CBA-BMS than BA-BMS (2.65+/-0.40 mm vs 2.52+/-0.4 mm, p<0.01) and % diameter stenosis (%DS)-post was less in CBA-BMS than BA-BMS (14.0+/-5.9% vs 16.3+/-6.8%, p<0.01). %DS-follow-up was subsequently less in CBA-BMS than BA-BMS (32.4+/-15.1% vs 35.4+/-15.3%, p<0.05) associated with lower rates of restenosis in CBA-BMS than BA-BMS (11.8% vs 19.6%, p<0.05) and less target lesion revascularization (TLR) in CBA-BMS than BA-BMS (9.6% vs 15.3%, p<0.05). Patients were divided into 4 groups based on the device used before stenting and IVUS use (IVUS-CBA-BMS: 137 patients; Angio-CBA-BMS: 123; IVUS-BA-BMS: 142; and Angio-BA-BMS: 119). At follow-up IVUS-CBA-BMS had a significantly lower restenosis rate (6.6%) than Angio-CBA-BMS (17.9%), IVUS-BA-BMS (19.8%) and Angio-BA-BMS (18.2%, p<0.05). Restenosis and TLR were significantly lower in CBA-BMS than BA-BMS. This favorable outcome was achieved because of the lower restenosis rate conferred by the IVUS-guided-CBA-BMS strategy (6.6%). The restenosis rates obtained with this strategy were comparable to those achieved with DES.

Full Text Available This paper considers the influence of thickness of multilayered nano-structured coatings Ti-TiN-(TiCrAlN and Zr-ZrN-(ZrCrNbAlN on tool life of metalcutting tools at various cutting speeds (vc = 250, 300, 350 and 400 m·min−1. The paper investigates the basic mechanical parameters of coatings and the mechanism of coating failure in scratch testing depending on thickness of coating. Cutting tests were conducted in longitudinal turning of steel C45 with tools with the coatings under study of various thicknesses (3, 5, and 7 µm, with an uncoated tool and with a tool with a “reference” coating of TiAlN. The relationship of “cutting speed vc—tool life T” was built and investigated; and the mechanisms were found to determine the selection of the optimum coating thickness at various cutting speeds. Advantages of cutting tools with these coatings are especially obvious at high cutting speeds (in particular, vc = 400 m·min−1. If at lower cutting speeds, the longest tool life is shown by tools with thicker coatings (of about 7 μm, then with an increase in cutting speed (especially at vc = 400 m·min−1 the longest tool life is shown by tools with thinner coating (of about 3 μm.

Grinding fluids have been commonly used during the grinding of tools for their cooling and lubricating effect since the hard, robust materials used for cutting tools are difficult to grind. Grinding fluids help prevent a drop in hardness due to burning of the cutting edge and keep chipping to an absolute minimum. However, there is a heightened awareness of the need to improve the work environment and protect the global environment. Thus, the present study is aimed at applying dry grinding, cooling-air grinding, cooling-air grinding with minimum quantity lubrication (MQL), and oil-based fluid grinding to manufacturing actual endmills (HSS-Co). Cutting tests were performed by a vertical machining center. The results indicated that the lowest surface inclination values and longest tool life were obtained by cooling-air grinding with MQL. Thus, cooling-air grinding with MQL has been demonstrated to be at least as effective as oil-based fluid grinding.

When processing ductile metals with high cutting speed, there is a need to take additional measures for a comfortable and safe formation and removal of chips. In the conditions of large-scale manufacture, it is recommended to produce flow chips in the form of short fragments, while in the conditions of small-lot and single-piece manufacture, it is reasonable to wrap the chips spirally with a rather small turn radius. Such way of chips formation reduces the time of its removal from the working...

This paper analyzes several types of cooling agents, their properties and how they can be chosen for a better heat dispersion resulting from the cutting process. An excessive heat in the cutting zone leads to excessive wear of the cutting tools, that leading finally to additional costs of their acquisition and due to wear is reached in cutting process more irregular surfaces. The coolant chosen can be a combination of different cooling fluids from the most simple and inexpensive to more complex, the difference between them being more appropriately cool the processing area. The fluid flow parameters of coolant can be influenced by the nature of the fluid or fluids used, the geometry of the nozzle in order to achieve a better dispersion of the lubricant on the area to be processed. A smaller amount of fluid is important in terms of the economy lubricant, because some of these lubricants are quite expensive. A minimal quantity of lubricant (MQL) may have a better impact on the environment and the health of the operator because the coolants in contact with overheated machined surface may develop a substantial amount of these gases that are not always beneficial to health.

When cuttingmetal with plasma arc cutting, the walls of the cut are narrower at the bottom than at the top. This lack of squareness increases as the cutting speed increases. A model of this phenomenon, affecting cut quality, is suggested. A thin liquid layer, which separates the plasma from the solid metal to be melted, plays a key role in the suggested model. This layer decreases heat transfer from the plasma to the solid metal; the decrease is more pronounced the higher the speed and the thicker the liquid metal layer. Since the layer is thicker at the bottom of the cut, the heat transfer effectiveness is lower at the bottom. The decrease in heat transfer effectiveness is compensated by the narrowness of the cut. The suggested model allows one to calculate the profile of the cut. The result of the calculations of the cutting speeds for plates of various thicknesses, at which the squareness of the cut is acceptable, agrees well with the speeds recommended by manufacturers. The second effect considered in the paper is the deflection of the plasma jet from the vertical at a high cutting speed. A qualitative explanation of this phenomenon is given. We believe the considerations of this paper are pertinent to other types of cutting with moving heat sources.

When processing ductile metals with high cutting speed, there is a need to take additional measures for a comfortable and safe formation and removal of chips. In the conditions of large-scale manufacture, it is recommended to produce flow chips in the form of short fragments, while in the conditions of small-lot and single-piece manufacture, it is reasonable to wrap the chips spirally with a rather small turn radius. Such way of chips formation reduces the time of its removal from the working area as well as facilitates its transportation and processing. In order to solve the problem of chip wrapping and breakage, almost all modern manufacturers of tools with replaceable many-sided plates (RMSP) followed the way of complication of tool faces and determination of the areas of effective chip breaking. On the one hand, the suggested solution turns out to be effective; however, as showed the analysis of recommended cutting modes for complex forms of RMSP made by leading manufacturers, they all correspond to the definite cross section of the cut-layer S/t=0.1.

Full Text Available Hybrid manufacturing processes that combine additive and machining operations are gaining relevance in modern industry thanks to the capability of building complex parts with minimal material and, many times, with process time reduction. Besides, as the additive and subtractive operations are carried out in the same machine, without moving the part, dead times are reduced and higher accuracies are achieved. However, it is not clear whether the direct material deposition after the machining operation is possible or intermediate cleaning stages are required because of the possible presence of residual cutting fluids. Therefore, different Laser Metal Deposition (LMD tests are performed on a part impregnated with cutting fluid, both directly and after the removal of the coolant by techniques such as laser vaporizing and air blasting. The present work studies the influence of the cutting fluid in the LMD process and the quality of the resulting part. Resulting porosity is evaluated and it is concluded that if the part surface is not properly clean after the machining operation, deficient clad quality can be obtained in the subsequent laser additive operation.

-laser cutting have until now limited its application in metalcutting. In this paper the first results of proof-of-principle studies applying a new approach (patent pending) for laser cutting with high brightness short wavelength lasers will be presented. In the approach, multi beam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metalcutting. The beam patterns in this study are created by splitting up beams from 2 single mode fibre lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W of single......The appearance of the high power high brilliance fibre laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating cutting laser, the CO2-laser. However, quality problems in fibre...

Full Text Available In the present work a review of the existing theories of chatter formation has been conducted and the weaknesses of the most widely accepted ‘Regenerative Chatter theory’ in explaining various phenomena related to chatter formation have been identified. An attempt has been made in this work to determine the common causes of chatter formation in different metalcutting operations, namely, turning, thread cutting and end milling conducted on plain carbon steel AISI 1040. Experimental investigations have been conducted during the above types of machining processes to identify the marks of instability and chatter on the formed chips. It has been identified that in all the three machining operations the chips formed show a common type of discreteness in the form of secondary saw teeth, which appear at the free edge of the chip. Mechanism of formation of these teeth has been studied and the frequencies of their formation have been determined for different cutting conditions. Apart from the secondary saw teeth primary saw teeth have also been identified at the main section of the chip and their frequencies were also determined. At the same time the natural vibrations of the main system components have been identified and the acceleration amplitudes at the prominent natural frequencies during actual machining were recoded using a dedicated vibration monitoring system. The frequencies of secondary chip serration and the natural frequencies of the system components were plotted against cutting speed. Acceleration amplitudes at the prominent natural frequencies were also plotted separately against cutting force. Based on comparison and analysis of these two frequency and amplitude graphs it was concluded that chatter (vibration with relatively high amplitude appears in the system when the frequency of secondary saw teeth approaches values equal to half or integer multiple of a prominent natural frequency of the system resulting in resonance. In the

Mobile laser technological complex MLTC-20 with radiation power 20 kW and radiation wavelength 1.07 μm created in SRC RF TRINITI on the base of a three cw fiber Yb lasers is used successfully at remote cutting of the metalworks at carrying out of the emergency-reduction works on the out of control gas wells. In this work the results of the investigation of the possibility and the efficiency of laser radiation application for remote cutting of metals on the emergency oil wells have been presented. Measurements of the mean absorption coefficient of the radiation of a cw fiber Yb laser under its propagation in a flame of burning oil in dependence on radiation intensity have been carried out. It was shown that at the intensity ~104 W/cm2 the absorption coefficient traverses the maximum where its value is equal to ~0.1 cm-1, and at the intensity increasing to the values 105 - 106 W/cm2 it stabilizes on a small level ~5·10-3 - 10-2 cm-1. It is established that the maximal velocity and the efficiency of remote cutting of the steel plates with a thickness up to 10 mm by the radiation with the intensity 106 W/cm2 exceed these factors at the intensity 104 W/cm2. The possibility of the efficient remote cutting of steel plate with a thickness of 60 mm by laser radiation having the power 7.5 kW and the intensity 105 W/cm2 has been demonstrated.

The purpose of this study widened knowledge on the use of the cutting tools out of metal carbide and to define of it the influence of the elements of the mode of cut on the behaviour of these tools during the machining of treated steel XC38 and untreated. This work aims at evolution determined in experiments of the wear of a cutting tool out of metal carbide with plate reported of P30 nuance for an operation of slide-lathing in turning on soaked and not hardened steel XC38 test-tubes. This research is based on the model of Taylor to determine the lifespan of the cutting tool according to the various parameters of cut, like the cutting speed Vc, the advance of cut a, the depth of cutting P. In order to express the operational limits of the tool for slide-lathing in a preventive way. The model makes it possible to determine the time of change of the tool and to regard it as constraint for the respect of the roughness of the work piece during a work of series in conventional machining.

Nowadays, an increasing concern about the treatment and disposal of waters contaminated by toxic heavy metals is noticed. The toxic pollutants must be removed from the sewage water which then is fed back into the materials cycle. Any candidate technology should result in reusable by-products. With this in mind, the aim of the present study is to test a low cost procedure for utilization of the carbonized waste, a product of PET (polyethylene terephthalate) bottles pyrolysis on sand bedding, for this purpose. Both the water present in PET bottles waste and combustion exhaust probably contribute to the conversion of carbon char to activated carbon directly within the pyrolysis oven. Preliminary results, obtained for several heavy metal ions under laboratory conditions are presented and discussed. Adsorption of heavy metals on the carbonized PET waste is tested by both the electrochemical methods and X-ray fluorescence spectrometry. A simple desorption procedure for the regeneration of prepared active carbon is proposed.

Full Text Available Microgrinding with micropencil grinding tools (MPGTs is a flexible and economic process to machine microstructures in hard and brittle materials. In macrogrinding, cooling and lubrication are done with metalcutting fluids; their application and influence is well researched. Although it can be expected that metalcutting fluids also play a decisive role in microgrinding, systematic investigations can hardly be found. A metalcutting fluid capable of wetting the machining process, containing quantities as small as 0.02% of the water-soluble fluid sodium dodecyl sulfate was tested in microgrinding experiments with MPGTs (diameter ~50 µm; abrasive grit size 2–4 µm. The workpiece material was hardened 16MnCr5.

Full Text Available Selective laser melting(SLM and direct metal laser sintering(DMLS are preferred additive manufacturing processes in producing complex physical products directly from CAD computer data, nowadays. The advancement of additive manufacturing promotes the design of internally cooled cutting tool for effectively used in removing generated heat in metal machining. Despite the utilisation of SLM and DMLS in a fabrication of internally cooled cutting tool, the level of accuracy of the parts produced remains uncertain. This paper aims at comparing the dimensional accuracy of SLM and DMLS in machining internally cooled cutting tool with a special focus on geometrical dimensions such as hole diameter. The surface roughness produced by the two processes are measured with contact perthometer. To achieve the objectives, geometrical dimensions of identical tool holders for internally cooled cutting tools fabricated by SLM and DMLS have been determined by using digital vernier calliper and various magnification of a portable microscope. In the current study, comparing internally cooled cutting tools made of SLM and DMLS showed that generally the higher degree of accuracy could be obtained with DMLS process. However, the observed differences in surface roughness between SLM and DMLS in this study were not significant. The most obvious finding to emerge from this study is that the additive manufacturing processes selected for fabricating the tool holders for internally cooled cutting tool in this research are capable of producing the desired internal channel shape of internally cooled cutting tool.

A method of welding an ultra-thin foil to the edge of a thicker sheet to form a vacuum insulation panel comprising the steps of providing an ultra-thin foil having a thickness less than 0.002, providing a top plate having an edge and a bottom plate having an edge, clamping the foil to the edge of the plate wherein the clamps act as heat sinks to distribute heat through the foil, providing a laser, moving the laser relative to the foil and the plate edges to form overlapping weld beads to weld the foil to the plate edges while simultaneously cutting the foil along the weld line formed by the overlapping beads.

Full Text Available The quest for optimization and quality of products has caused many organizations to eliminate the inefficiencies of their production processes, to reduce costs and increase profitability so that they can ensure their survival in the current economic scenario. Thus, it is necessary to use methods and techniques that help in getting better results. Minimize waste and promote overall product quality has become one of the main goals of the organizations. This study is Bibliographically the concept of Lean Manufacturing (Lean Manufacturing, which focused on eliminating waste, served as the basis for this study, which through an action - research aimed to applying lean practices for performance improvement the laser cutting process for an industry of the metalmechanic sector. The results show that the identification of the main sources of waste and the constant search for its elimination brought productivity advantages for the company, by reducing the processes of machines and minimize production costs time. With this, the company started to produce more, and improve their processes in the proper use of available resources.

New developments in flexible electronics require metal films to adhere to polymer substrates. Measuring the interfacial adhesion of these systems is challenging, requiring the formulation of new techniques and models. A strategy to measure the adhesion of Cr-polyethylene terephthalate (PET) interfaces using tensile straining and buckle formation is presented in this article. Focused ion beam cross-sectioning of the buckles reveals that the polymer substrate can locally fail, which may lead to an overestimate of adhesion. Cr-PET adhesion energy of 9.4 ± 1.6 J/m2 is determined with the present approach.

of single mode fiber laser power. Burr free cuts in 1 mm steel and aluminum and in 1 and 2 mm AISI 304 stainless steel is demonstrated over a wide range of cutting rates. The industrial realization of this approach is foreseen to be performed by either beam patterning by diffractive optical elements......The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber...... to control the melt flow out of the cut kerf resulting in improved cut quality in metalcutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

The rise in cutting temperatures during the machining process can influence the final quality of the machined part. The impact of cutting temperatures is more critical when machining composite-metal stacks and fiber metal laminates due to the stacking nature of those hybrids which subjects the composite to heat from direct contact with metallic part of the stack and the evacuated hot chips. In this paper, the workpiece surface temperature of two grades of fiber metal laminates commercially know as GLARE is investigated. An experimental study was carried out using thermocouples and infrared thermography to determine the emissivity of the upper, lower and side surfaces of GLARE laminates. In addition, infrared thermography was used to determine the maximum temperature of the bottom surface of machined holes during drilling GLARE under dry and minimum quantity lubrication (MQL) cooling conditions under different cutting parameters. The results showed that during the machining process, the workpiece surface temperature increased with the increase in feed rate and fiber orientation influenced the developed temperature in the laminate.

Full Text Available The rise in cutting temperatures during the machining process can influence the final quality of the machined part. The impact of cutting temperatures is more critical when machining composite-metal stacks and fiber metal laminates due to the stacking nature of those hybrids which subjects the composite to heat from direct contact with metallic part of the stack and the evacuated hot chips. In this paper, the workpiece surface temperature of two grades of fiber metal laminates commercially know as GLARE is investigated. An experimental study was carried out using thermocouples and infrared thermography to determine the emissivity of the upper, lower and side surfaces of GLARE laminates. In addition, infrared thermography was used to determine the maximum temperature of the bottom surface of machined holes during drilling GLARE under dry and minimum quantity lubrication (MQL cooling conditions under different cutting parameters. The results showed that during the machining process, the workpiece surface temperature increased with the increase in feed rate and fiber orientation influenced the developed temperature in the laminate.

In the paper a description of heat transfer in a one-dimensional two-layered metal film is considered. The fuzzy coupled lattice Boltzmann equations for electrons and phonons supplemented by appropriate boundary and initial conditions are applied to analyse the thermal process in a thin metal film. The model with fuzzy values of relaxation times and boundary-initial conditions for gold and titanium is proposed. The problem considered is solved by the fuzzy lattice Boltzmann method using α-cuts and the rules of directed interval arithmetic. The application of α-cuts allows one to avoid complicated arithmetical operations in the fuzzy numbers set. In the final part of the paper an example for a numerical solution is presented.

For the decommissioning of nuclear installations, methods and tools for the dismantling of complicated metallic components with great material thickness are needed. The method of underwater plasma arc cutting offers the possibility for the dismantling of highly activated components because of the shielding effect of water. Up to now the tools for the underwater method are only available for simple contours. Target of the project was the development of a plasma arc cutting technique for the dismantling of complicated components and of a control and measurement system. (orig./DG) [de

The present joint study performed by the Commissariat a l'energie atomique and the Universitaet Hannover and coordinated by the Commission of the European Communities was intended to analyse the results generated in a number of research contracts concerned with cutting tests in air and underwater, with consideration of the prevailing working conditions. The analysis has led to a large database, giving broadly-assessed information for the dismantling of radioactive components. The range of study was enlarged, where possible, to include recently obtained results outside the present research programme, consideration also being given to supplementary cutting tools and filtration systems not covered by the present programme. Data was concentrated in structured information packages on practical experience available for a series of cutting tools and filters. These were introduced into a computerized user-friendly databank, to be considered as a first-stage development, which should be continuously updated and possibly oriented in the future to an expert system

Machining Glass fibre aluminium reinforced epoxy (GLARE) is cumbersome due to distinctively different mechanical and thermal properties of its constituents, which makes it challenging to achieve damage-free holes with the acceptable surface quality. The proposed work focuses on the study of the machinability of thin ( 2.5 mm) GLARE laminate. Drilling trials were conducted to analyse the effect of feed rate and spindle speed on the cutting forces and hole quality. The resulting hole quality metrics (surface roughness, hole size, circularity error, burr formation and delamination) were assessed using surface profilometry and optical scanning techniques. A three dimensional (3D) finite-element (FE) model of drilling GLARE laminate was also developed using ABAQUS/Explicit to help understand the mechanism of drilling GLARE. The homogenised ply-level response of GLARE laminate was considered in the FE model to predict cutting forces in the drilling process.

The aim of this study is to develop a new method for cuttingmetal components of nuclear power plants, which produces virtually no secondary waste. In this method, a controlled intergranular fissure is produced in a heated area of the component by the addition of a molten material which gives rise to the formation of brittle compounds. With the presence of molten metal, the material or alloys in which we have tension stresses can have a brittle intergranular failure. Generally the failure occurs in a defined temperature range. The tension stresses are created by the thermal gradient induced during the local heating. At the same time, the molten metal is added. Our work has been developed in two directions: Study on the maximum thickness (presently it is potentially possible to cut thick sheets up to 100 mm); dismantling of nuclear parts as tubes, cans, hot cell walls (we are on the beginning of the development in this field of work). (author)

Full Text Available Morphology, physicochemical properties, chemical composition of post-galvanized sewage sludge from Screw Factory in Łańcut, leachability and mobility of metals has been analyzed. The analyses with the use of scanning electron microscope with an adapter to perform chemical analysis of microsites (EDS showed that the material is characterized by a high fragmentation and a predominant number of irregularly shaped grains. The sewage sludge is alkaline with a large loss of ignition (34.6% and small bulk density (< 1 g/cm3. The EDS analyses evidenced presence of oxygen, silicon, calcium, chromium, iron and zinc in all examined areas, and presence of manganese and copper in selected areas indicating a non-uniform distribution of metals in the sewage sludge. Within one-stage mineralization and FAAS technique a predominant share of calcium, zinc and iron in terms of dry matter was recorded in the sewage sludge. The contents of Co, Cr, Cu, K, Mn, Ni and Pb in sewage sludge are below 1%. Evaluation of mobility and leaching of metals in sewage sludge was carried out by means of two parameters: accumulation coefficient of mobile fractions and leaching level related to the mass solubility of sewage sludge. The results indicate that the short-term or long-term storage of not inactivated post-galvanized sewage sludge can result in release of metals.

In this paper a short review of the development trends in laser cutting will be given.The technology, which is the fastest expanding industrial production technology will develop in both its core market segment: Flat bed cutting of sheet metal, as it will expand in heavy industry and in cutting...... of 3-dimensional shapes.The CO2-laser will also in the near future be the dominating laser source in the market, although the new developments in ND-YAG-lasers opens for new possibilities for this laser type....

This study attempts to understand the intrinsic impact of different morphologies of nanocrystals on their electrochemical stripping behaviors toward heavy metal ions. Two differently shaped Fe3O4 nanocrystals, i.e., (100)-bound cubic and (111)-bound octahedral, have been synthesized for the experiments. Electrochemical results indicate that Fe3O4 nanocrystals with different shapes show different stripping behaviors toward heavy metal ions. Octahedral Fe3O4 nanocrystals show better electrochemical sensing performances toward the investigated heavy metal ions such as Zn(II), Cd(II), Pb(II), Cu(II), and Hg(II), in comparison with cubic ones. Specifically, Pb(II) is found to have the best stripping performance on both the (100) and (111) facets. To clarify these phenomena, adsorption abilities of as-prepared Fe3O4 nanocrystals have been investigated toward heavy metal ions. Most importantly, combined with theoretical calculations, their different electrochemical stripping behaviors in view of facet effects have been further studied and enclosed at the level of molecular/atom. Finally, as a trial to find a disposable platform completely free from noble metals, the potential application of the Fe3O4 nanocrystals for electrochemical detection of As(III) in drinking water is demonstrated.

A direct diode laser was built with > 800 W output power at 940 nm to 980 nm. The radiation is coupled into a 100 µm fiber and the NA ex fiber is 0.17. The laser system is based on pump modules that are wavelength stabilized by VBGs. Dense and coarse wavelength multiplexing are realized with commercially available ultra-steep dielectric filters. The electro-optical efficiency is above 30%. Based on a detailed analysis of losses, an improved e-o-efficiency in the range of 40% to 45% is expected in the near future. System performance and reliability were demonstrated with sheet metalcutting tests on stainless steel with a thickness of 4.2 mm.

With the demand against complicating working techniques for a background, foundations of the consideration for each of the lubricants in future are outlined. 1. Cutting oils: From the standpoint of speeding up and fireproofing, share of water-soluble type has come up to 30-40%. In this type, emulsifying dispersants and preservatives are combined. 2. Rolling oils: According to thinning of the standard thickness of steel plates, pressure of contacting surfaces has come up to 300 kg/mm{sup 2}(max.) and slip speed has increased too. In stainless steel plates, in order to get rid of the heat-streak (baking streak originated from wearing-out of oil film) shifting from neat oil to emulsion type is required. 3. Quenching oils: Following two systems are recent tendencies, the mineral oil system having excellent thermostability or the water system containing polyalkylneglycol etc., but the latter is expected from the viewpoint of fireproofing. 4. Rust preventive oils: As this oils do not aim at the rust prevention for long term, degreasing property is required. 20 refs., 5 figs., 1 tab.

Modern laser technology is continuously opening up new fields of applications. Driven by the development of increasingly efficient laser sources, the new technology is successfully entering classical applications such as 3D cutting and welding of metals. Especially in light weight applications in the automotive industry laser manufacturing is key. Only by this technology the reduction of welding widths could be realised as well as the efficient machining of aluminium and the abrasion free machining of hardened steel. The paper compares the operation of different laser types in metal machining regarding wavelength, laser power, laser brilliance, process speed and welding depth to give an estimation for best use of single mode or multi mode lasers in this field of application. The experimental results will be presented by samples of applied parts. In addition a correlation between the process and the achieved mechanical properties will be made. For this application JENOPTIK Automatisierungstechnik GmbH is using the BIM beam control system in its machines, which is the first one to realize a fully integrated combination of beam control and robot. The wide performance and wavelength range of the laser radiation which can be transmitted opens up diverse possibilities of application and makes BIM a universal tool.

A cutting apparatus includes a support table mounted for movement toward and away from a workpiece and carrying a mirror which directs a cutting laser beam onto the workpiece. A carrier is rotatably and pivotally mounted on the support table between the mirror and workpiece and supports a conduit discharging gas toward the point of impingement of the laser beam on the workpiece. Means are provided for rotating the carrier relative to the support table to place the gas discharging conduit in the proper positions for cuts made in different directions on the workpiece.

The efficacy of cutting or plain balloon angioplasty (CBA or PBA) has not been analyzed for the treatment of drug-eluting stent (DES) restenosis vs bare metal stent (BMS) restenosis. The 252 in-stent restenosis (ISR) lesions in 224 consecutive patients treated by CBA (n=167) or PBA (n=85) between July 2002 and December 2007 were analyzed. At 6-month angiographic and 12-month clinical follow-up, CBA and PBA showed similar efficacies: repeat-ISR (37.0% vs 37.8%, P=0.90), late loss (0.62+/-0.60 vs 0.61+/-0.47 mm, P=0.92), and target lesion revascularization (18.3% vs 22.4%, P=0.50). This comparable efficacy was maintained for treatment in the DES-ISR and BMS-ISR subgroups. However, target lesion-related myocardial infarction (n=9) occurred more frequently in the CBA than in the PBA arm (6.2% vs 0%, P=0.03), most of which developed early after ISR treatment (n=7; 54+/-26 days). Independent predictors of repeat-ISR were diffuse ISR and smaller pretreatment minimal lumen diameter, both of which might imply heavier plaque burden in the ISR group. Plain or cutting balloon angioplasty for ISR seems to be comparable, as the angiographic or clinical endpoints were not affected by initial stent type but by parameters related to the plaque burden of the ISR lesion. However, CBA might be associated with higher risk of myocardial infarction than PBA, suggesting more attention to dual-antiplatelet therapy after its use for ISR.

Full Text Available Cutting temperature is very important parameter of cutting process. Around 90% of heat generated during cutting process is then away by sawdust, and the rest is transferred to the tool and workpiece. In this research cutting temperature was measured with artificial thermocouples and question of investigation of metal machinability from aspect of cutting temperature was analyzed. For investigation of material machinability during turning artificial thermocouple was placed just below the cutting top of insert, and for drilling thermocouples were placed through screw holes on the face surface. In this way was obtained simple, reliable, economic and accurate method for investigation of cutting machinability.

metal vapour from the cut kerf is spread in air. In cutting of irradiated material, debris and metal vapour creates airborne activity, which may be harmful for people working nearby, whereas, underwater cutting is advantageous in terms of a narrow. HAZ adjacent to the laser cut surface providing better samples for the analysis.

The structure of the rare-cutting restriction endonuclease NotI, which recognizes the 8 bp target 5'-GCGGCCGC-3', has been solved with and without bound DNA. Because of its specificity (recognizing a site that occurs once per 65 kb), NotI is used to generate large genomic fragments and to map DNA methylation status. NotI contains a unique metal binding fold, found in a variety of putative endonucleases, occupied by an iron atom coordinated within a tetrahedral Cys4 motif. This domain positions nearby protein elements for DNA recognition, and serves a structural role. While recognition of the central six base pairs of the target is accomplished via a saturated hydrogen bond network typical of restriction enzymes, the most peripheral base pairs are engaged in a single direct contact in the major groove, reflecting reduced pressure to recognize those positions. NotI may represent an evolutionary intermediate between mobile endonucleases (which recognize longer target sites) and canonical restriction endonucleases.

around which Bugkalot society revolves, but also a reflection on anthropological theory and writing. Focusing on the transgressive acts through which masculinity is performed, this book explores the idea of the cosmic cut, the ritual act that enables the Bugkalot man to momentarily hold still the chaotic......For the first time in over 30 years, a new ethnographic study emerges on the Bugkalot tribe, more widely known as the Ilongot of the northern Philippines. Exploring the notion of masculinity among the Bugkalot, Cutting Cosmos is not only an experimental, anthropological study of the paradoxes...

The mechanism of remote cutting of steel plates by radiation of a high-power repetitively pulsed CO 2 laser is theoretically studied. The models of melt removal by the gravity force and the recoil pressure of material vapour are proposed and the sufficient conditions for the initiation of cutting are determined. A numerical model of a thermally thin plate was employed to describe the cutting for large focal spots. (interaction of laser radiation with matter. laser plasma)

Drug-eluting stents (DES) are superior to bare metal stents (BMS) for treating ostial left anterior descending artery (LAD) lesions, but DES is not suitable for all patients in real life practice. We hypothesize that cutting balloon angioplasty (CBA) followed by BMS (CBA + BMS) for treating ostial LAD lesions is an alternative strategy. In our study, 101 consecutive patients (51 with DES and 50 with CBA + BMS) with ostial LAD stenting were included for retrospective investigation between November 2003 and May 2005. The target vessel diameter was > or =3.0 mm. We compared the DES group with the CBA + BMS group, the rates of restenosis (10.3% versus 17.9%, p = 0.386), target lesion revascularization (TLR) (5.88% versus 10%, p = 0.487) and major adverse cardiac events (MACE) (7.84% versus 12%, p = 0.525) were similar at 6-8 months angiographic follow-up, but there were higher bleeding events in the DES group (p = 0.033). During a 2-year clinical follow-up, no myocardial infarction occurred in the 2 groups, the rates of TLR (7.84% versus 10%, p = 0.741) and MACE (9.8% versus 12%, p = 0.723) were also similar. The MACE-free survival rate was 90.2% versus 88 % (p = 0.723). The CBA + BMS combination has a good long-term clinical effect in the treatment of ostial LAD lesions; it might be an alternative strategy for patients with contraindication for DES implantation, or patients who cannot endure long-term dual antiplatelet medication, or in elderly patients.

In some applications, laser cutting of wedge surfaces cannot be avoided in sheet metal processing and the quality of the end product defines the applicability of the laser-cutting process in such situations. In the present study, CO 2 laser cutting of the wedge surfaces as well as normal surfaces (normal to laser beam axis) is considered and the end product quality is assessed using the international standards for thermal cutting. The cut surfaces are examined by the optical microscopy and geometric features of the cut edges such as out of flatness and dross height are measured from the micrographs. A neural network is introduced to classify the striation patterns of the cut surfaces. It is found that the dross height and out of flatness are influenced significantly by the laser output power, particularly for wedge-cutting situation. Moreover, the cut quality improves at certain value of the laser power intensity.

The operation of numerically controlled machine tools is interactively simulated. Four programs were developed to graphically display the cutting paths for a Monarch lathe, Cintimatic mill, Strippit sheet metal punch, and the wiring path for a Standard wire wrap machine. These programs are run on a IMLAC PDS-ID graphic display system under the DOS-3 disk operating system. The cutting path analysis programs accept input via both paper tape and disk file.

A control rod transferred under water in a vertically suspended state is postured horizontally at such a water depth that radiations can be shielded, and then it is cut to a dropping speed limiting portion and a cross-like main body. The separated cross-like main body portion is further cut in the longitudinal direction and separated into a pair of cut pieces each having an L-shaped cross section. A disk like metal saw is used as a cutting tool. Alternatively, a plasma jet cutter or a melting-type water jet cutter is used as a cutting tool. Then, since the spent control rod to be cut is postured horizontally under water, the water depth for the cutting position can be reduced. As a result, the cutting state using the cutting tool can be observed by naked eyes from the position above the water surface thereby enabling to perform the cutting operation reliably. (N.H.)

Full Text Available The production lines used for manufacturing U-shaped profiles are very complex and they must have high productivity. One of the most important stages of the fabrication process is the cutting-off. This paper presents the experimental research and analysis of the durability of the cutting tools used for cutting-off U-shaped metal steel profiles. The results of this work can be used to predict the durability of the cutting tools.

It has been suggested previously that copper transport in Escherichia coli is mediated by the products of at least six genes, cutA, cutB, cutC, cutD, cutE, and cutF. A mutation in one or more of these genes results in an increased copper sensitivity (D. Rouch, J. Camakaris, and B. T. O. Lee, p. 469-477, in D. H. Hamer and D. R. Winge, ed., Metal Ion Homeostasis: Molecular Biology and Chemistry, 1989). Copper-sensitive cutC and cutF mutants were transformed with a genomic library of E. coli, a...

Interest in ceramics as a high speed cutting tool material is based primarily on favorable material properties. As a class of materials, ceramics possess high melting points, excellent hardness and good wear resistance. Unlike most metals, hardness levels in ceramics generally remain high at elevated temperatures which means that cutting tip integrity is relatively unaffected at high cutting speeds. Ceramics are also chemically inert against most workmetals.

... a sign that your child has thoughts of suicide. If you are concerned your child is cutting, learn the warning signs, methods of ... your child’s risk of cutting. While thoughts of suicide aren’t common with cutting, your child could accidentally cut deep enough or cut an ...

In aluminium matrix composites, reinforcement of hard ceramic particle present inside the matrix which causes tool wear, high cutting forces and poor surface finish during machining. This paper focuses on effect of cutting parameters on thrust force, surface roughness and burr height during drilling of MMCs. In the present work, discuss the influence of spindle speed and feed rate on drilling the pure base alloy (Al-2219), mono composite (Al- 2219+8% B4C) and hybrid composite (Al-2219+8%B4C+3%Gr). The composites were fabricated using liquid metallurgy route. The drilling experiments were conducted by CNC machine with TiN coated HSS tool, M42 (Cobalt grade) and carbide tools at various spindle speeds and feed rates. The thrust force, surface roughness and burr height of the drilled hole were investigated in mono composite and hybrid composite containing graphite particles, the experimental results show that the feed rate has more influence on thrust force and surface roughness. Lesser thrust force and discontinuous chips were produced during machining of hybrid composites when compared with mono and base alloy during drilling process. It is due to solid lubricant property of graphite which reduces the lesser thrust force, burr height and lower surface roughness. When machining with Carbide tool at low feed and high speeds good surface finish was obtained compared to other two types of cutting tool materials.

On decommissioning of nuclear facilities, the thermal cutting technique such as an oxygen-acetylene gas cutting and a plasma arc cutting are generally used for cutting massive and thick steel structures in consideration with cutting speed and control performance. These techniques generate dust, smoke, aerosol and a large quantity of secondary waste. Mechanical cutting technique has an advantage of small amount of secondary waste, and the metal chips from the kerf recovered easily compared with these thermal cutting technique. The remote mechanical cutting system for highly activated RPV has been developed with the manner which achieves the safety and cost effectiveness. The development has been performed on consignment to RANDEC from the Science and Technology Agency of Japan. (author)

Metalcutting is an important machining operation in the manufacture of almost all engineering components. Cutting technology has undergone several changes with the development of machine tools and cutting tools to meet challenges posed by newer materials, complex shapes, product miniaturization and competitive environments. In this paper, challenges in macro and micro cutting are brought out. Conventional and micro end-milling are included as illustrative examples and details are presented along with discussion. Lengthy equations are avoided to the extent possible, as the emphasis is on the basic concepts.

The laser cutting of color metals and alloys by a thickness more than 2 mm has significant difficulties due to high reflective ability and large thermal conduction. We made it possible to raise energy efficiency and quality of laser cutting by using a laser processing system (LPS) consisting both of the YAG:Nd laser with passive Q-switching on base of LiF:F2- crystals and the CO2 laser. A distinctive feature of the LPS is that the radiation of different lasers incorporated in a coaxial beam has simultaneously high level of peak power (more than 400 kW in a TEM00 mode) and significant level of average power (up to 800 W in a TEM01 mode of the CO2 laser). The application of combined radiation for cutting of an aluminum alloy of D16 type made it possible to decrease the cutting energy threshold in 1.7 times, to increase depth of treatment from 2 up to 4 mm, and velocity from 0.015 up to 0.7 m/min, and also to eliminate application of absorptive coatings. At cutting of steels the velocity of treatment was doubled, and also an oxygen flow was eliminated from the technological process and replaced by the air. The obtained raise of energy efficiency and quality of cutting is explained by an essential size reducing of a formed penetration channel and by the shifting of a thermal cutting mode from melting to evaporation. The evaluation of interaction efficiency of a combined radiation was produced on the basis of non-stationary thermal-hydrodynamic model of a heating source moving as in the cutting direction, and also into the depth of material.

In the automotive industry as well as in other industries ecological aspects regarding energy savings are driving new technologies and materials, e.g. lightweight materials as aluminium or press hardened steels. Processing such parts especially complex 3D shaped parts laser manufacturing has become the key process offering highest efficiency. The most established systems for 3D cutting applications are based on gantry systems. The disadvantage of those systems is their huge footprint to realize the required stability and work envelope. Alternatively a robot based system might be of advantage if accuracy, speed and overall performance would be capable processing automotive parts. With the BIM "beam in motion" system, JENOPTIK Automatisierungstechnik GmbH has developed a modular robot based laser processing machine, which meets all OEM specs processing press hardened steel parts. A benchmark of the BIM versus a gantry system was done regarding all required parameters to fulfil OEM specifications for press hardened steel parts. As a result a highly productive, accurate and efficient system can be described based on one or multiple robot modules working simultaneously together. The paper presents the improvements on the robot machine concept BIM addressed in 2012 [1] leading to an industrial proven system approach for the automotive industry. It further compares the performance and the parameters for 3D cutting applications of the BIM system versus a gantry system by samples of applied parts. Finally an overview of suitable applications for processing complex 3D parts with high productivity at small footprint is given.

An analysis of cutting fluid performance in different metalcutting operations is presented, based on experimental investigations in which type of operation, performance criteria, work material, and fluid type are considered. Cutting fluid performance was evaluated in turning, drilling, reaming a...

In this paper a short review of the development trends in laser cutting will be given. The technoloty which is the fastest expanding industrial production technology will develop in both its core market segment: Flat bed cutting of sheet metal as it will expand in heavy industry and in cutting of 3...

To cut inlay from a stack of glued veneer a CO2 HEBAR-1A laser was used. For setting optimal working parameters of the set used in industrial production of inlay the following elements were defined: the shape and dimensions of the cutting fissure, the dependence between the width of the cutting fissure and the speed with which the laser beam moves and the total thickness of the stack of veneer sheets, the application of the laser for cutting various patterns. Computer aided designing and computer steering of the laser beam enables fast and precise production of large numbers of inlay elements not only from wood but also from other materials like glass, stone, metal, etc. Taking into consideration the high running cost of such a laser set and its very big production only few factories or even one factory in the given area could produce inlay ready for gluing. Further investigation should be carried out on this field particularly considering the lowering of costs not only in inlay production but generally where cutting of wood is concerned.

Over the past few years, the Institute for Materials Research of the University of Hanover developed a new product family (Contact-Arc-Metal-X) of electrothermal techniques for underwater cutting of metal structures. This CAMX technology comprises contact arc metalcutting by means of a sword-shaped electrode, contact arc metal grinding with a rotating electrode, and contact arc metal drilling with an integrated interlocking mechanism. CAMC is characterized by its capability to cut components with complex structures. Undercuts and cavities constitute no obstacles in the process. CAMG is a technique for straight cutting characterized by its high cutting speeds. CAMD is able to produce countersunk boreholes and holes of any geometry. The integrated tensioning mechanism allows parts to be gripped and transported which could not be handled by conventional gripper systems. (orig.) [de

This is a survey, with 198 literature references, of the papers published in the fields of welding and cutting within the last three years. The subjects dealt with are: weldability of the materials - Welding methods - Thermal cutting - Shaping and calculation of welded joints - Environmental protection in welding and cutting. (orig.) [de

In Kawasaki Heavy Industries, Ltd., the development of a remote dismantling system by underwater plasma arc cutting process has been advanced, expecting its application to the dismantling and removal of nuclear reactor facilities. In the previous two reports, the fundamental experimental results such as the comparison of the cutting capability in air and in water were shown, but this time, the remote automatic cutting of wedge-shaped specimens was carried out, using a newly installed manipulator for underwater works, therefore its outline is reported. Also the cutting experiment by overhead position and vertical position was performed by using the same equipment, and comparison was made with the cutting capability by downhand and horizontal positions. It is important to grasp the cutting characteristics in the case of upward advancing and downward advancing cuttings by overhead and vertical positions when the cutting of pressure vessels and horizontal pipes into rings is supposed. The experimental apparatus, the cutting conditions, the testing method and the test results of the cutting capability test, the test of changing direction during cutting, and the remote cutting of pipes into rings are described. The underwater plasma arc cutting can cut all metals, the cutting speed is relatively high, and the apparatus is simple and compact. (Kako, I.)

A method for cutting with a laser beam where an oxygen-hydrocarbon reaction is used to provide auxiliary energy to a metal workpiece to supplement the energy supplied by the laser. Oxygen is supplied to the laser focus point on the workpiece by a nozzle through which the laser beam also passes. A liquid hydrocarbon is supplied by coating the workpiece along the cutting path with the hydrocarbon prior to laser irradiation or by spraying a stream of hydrocarbon through a nozzle aimed at a point on the cutting path which is just ahead of the focus point during irradiation.

Owing to their desirable strength-to-weight characteristics, carbon fibre reinforced polymer composites have been favourite materials for structural applications in different industries such as aerospace, transport, sports and energy. They provide a weight reduction in whole structure and consequently decrease fuel consumption. The use of lightweight materials such as titanium and its alloys in modern aircrafts has also increased significantly in the last couple of decades. Titanium and its alloys offer high strength/weight ratio, high compressive and tensile strength at high temperatures, low density, excellent corrosion resistance, exceptional erosion resistance, superior fatigue resistance and relatively low modulus of elasticity. Although composite/metal hybrid structures are increasingly used in airframes nowadays, number of studies regarding drilling of composite/metal stacks is very limited. During drilling of multilayer materials different problems may arise due to very different attributes of these materials. Machining conditions of drilling such structures play an important role on tool wear, quality of holes and cost of machining.. The research work in this thesis is aimed to investigate drilling of CFRP/Ti6Al4V hybrid structure and to optimize process parameters and drill geometry. The research work consist complete experimental study including drilling tests, in-situ and post measurements and related analysis; and finite element analysis including fully 3-D finite element models. The experimental investigations focused on drilling outputs such as thrust force, torque, delamination, burr formation, surface roughness and tool wear. An algorithm was developed to analyse drilling induced delamination quantitatively based on the images. In the numerical analysis, novel 3-D finite element models of drilling of CFRP, Ti6Al4V and CFRP/Ti6Al4V hybrid structure were developed with the use of 3-D complex drill geometries. A user defined subroutine was developed

The study discussed in this report was a cost/benefit analysis to determine: (1) whether explosive cutting is cost effective in comparison with alternative metal sectioning methods and (2) whether explosive cutting would reduce radiation exposure or provide other benefits. Two separate approaches were pursued. The first was to qualitatively assess cutting methods and factors involved in typical sectioning cases and then compare the results for the cutting methods. The second was to prepare estimates of work schedules and potential radiation exposures for candidate sectioning methods for two hypothetical, but typical, sectioning tasks. The analysis shows that explosive cutting would be cost effective and would also reduce radiation exposure when used for typical nuclear facility sectioning tasks. These results indicate that explosive cutting should be one of the principal cutting methods considered whenever steel or similar metal structures or equipment in a nuclear facility are to be sectioned for repair or decommissioning. 13 figures, 7 tables

An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

The dictionary contains approximately 40 000 entries covering all aspects of welding technology. It is based on the evaluation of numerous English, American and German sources. This comprehensive and up to date dictionary will be a reliable and helpful aid in evaluation and translating. The dictionary covers the following areas: Welding: gas welding, arc welding, gas shielded welding, resistance welding, welding of plastics, special welding processes; Cutting: flame cutting, arc cutting and special thermal cutting processes; Soldering: brazing and soldering; Other topics: thermal spraying, metal to metal adhesion, welding filler materials and other consumables, test methods, plant and equipment, accessories, automation, welding trade, general welding terminology. (orig./HP) [de

... requirements of § 1915.154. (e) Before welding, cutting or heating is commenced in enclosed spaces on metals...) Immediately after welding, cutting or heating is commenced in enclosed spaces on metal covered by soft and... 29 Labor 7 2010-07-01 2010-07-01 false Welding, cutting and heating in way of preservative...

Full Text Available One of research methods in metalcutting process is to measure hardness in the contact zone between cutting tool and workpiece. The objective of the performed research was to determine thickness and hardness of the superficial layer of cut surface due to cutting process, both orthogonal and complex cutting. The most important finding was that thickness of the superficial hardened layer is very thin under considered conditions, less than 0.01 … 0.02 mm. This research should be continued.

It has been suggested previously that copper transport in Escherichia coli is mediated by the products of at least six genes, cutA, cutB, cutC, cutD, cutE, and cutF. A mutation in one or more of these genes results in an increased copper sensitivity (D. Rouch, J. Camakaris, and B. T. O. Lee, p. 469-477, in D. H. Hamer and D. R. Winge, ed., Metal Ion Homeostasis: Molecular Biology and Chemistry, 1989). Copper-sensitive cutC and cutF mutants were transformed with a genomic library of E. coli, and copper-tolerant transformants were selected. Two distinct clones were identified, each of which partially restores copper tolerance in both the cutC and cutF mutants of E. coli. Subcloning, physical mapping, and sequence analysis have revealed that the cutC gene is located at 42.15 min on the E. coli genome and encodes a cytoplasmic protein of 146 amino acids and that the cutF gene is located at 4.77 min on the E. coli genome and is allelic to the nlpE gene independently identified by Silhavy and coworkers (W. B. Snyder, L. J. B. Davis, P. N. Danese, C. L. Cosma, and T. J. Silhavy, J. Bacteriol. 177:4216-4223, 1995). Results from the genetic mapping of the copper-sensitive mutations in the cutF mutant and sequencing of the cutC and cutF (nlpE) alleles from both cutC and cutF mutants indicate that both the cutC and cutF mutants are in fact double mutants altered in these two genes, and mutations in both the genes appear to be required for the copper-sensitive phenotype in each mutant.

In the field of food engineering, cutting is usually classified as a mechanical unit operation dealing with size reduction by applying external forces on a bulk product. Ultrasonic cutting is realized by superpositioning the macroscopic feed motion of the cutting device or of the product with a microscopic vibration of the cutting tool. The excited tool interacts with the product and generates a number of effects. Primary energy concentration in the separation zone and the modification of contact friction along the tool flanks arise from the cyclic loading and are responsible for benefits such as reduced cutting force, smooth cut surface, and reduced product deformation. Secondary effects such as absorption and cavitation originate from the propagation of the sound field in the product and are closely related to chemical and physical properties of the material to be cut. This chapter analyzes interactions between food products and ultrasonic cutting tools and relates these interactions with physical and chemical product properties as well as with processing parameters like cutting velocity, ultrasonic amplitude and frequency, and tool design.

The primary circuit structures of different nuclear powerplants are constructed out of stainless steels, ferritic steels, plated ferritic steels and alloys of aluminium. According to the level of the specific radiation of these structures, it is necessary for dismantling to work with remote controlled cutting techniques. The most successful way to protect the working crew against exposure of radiation is to operate underwater in different depths. The following thermal cutting processes are more or less developed to work under water: For ferritic steels only - flame cutting; For ferritic steels, stainless steels, cladded steels and aluminium alloys - oxy-arc-cutting, arc-waterjet-cutting with a consumable electrode, arc-saw-cutting, plasma-arc-cutting and plasma-arc-saw. The flame cutting is a burning process, all the other processes are melt-cutting processes. This paper explains the different techniques, giving a short introduction of the theory, a discussion of the possibilities with the advantages and disadvantages of these processes giving a view into the further research work in this interesting field. (author)

Full Text Available This present work deals with the features of trim cut wire EDM machining of Nimonic 80A in terms of machining parameters, to predict material removal rate (MRR, surface roughness (Ra, wire wear ratio (WWR and microstructure analysis. Trim cut is performed after rough cut to remove the rough layer deposited after machining due to melting and re-solidification of the eroded metal from workpiece as well as from wire electrode. Taguchi’s design of experiments methodology has been used for planning and designing the experiments. The relative significance of various factors has also been evaluated and analyzed using ANOVA. The results clearly indicate trim cut potential for high surface finish compared to rough cut machining.

An accessible business school population of undergraduate students was investigated in three independent, but related studies to determine effects on grades due to cutting class and failing to take advantage of optional reviews and study quizzes. It was hypothesized that cutting classes harms exam scores, attending preexam reviews helps exam…

There remains significant concern about the long-term safety of drug-eluting stents (DES). However, bare metal stents (BMS) have been used safely for over two decades. There is therefore a pressing need to explore alternative strategies for reducing restenosis with BMS. This study was designed to examine whether IVUS-guided cutting balloon angioplasty (CBA) with BMS could convey similar restenosis rates to DES. In the randomised REstenosis reDUction by Cutting balloon angioplasty Evaluation (REDUCE III) study, 521 patients were divided into four groups based on device and IVUS use before BMS (IVUS-CBA-BMS: 137 patients; Angio-CBA-BMS: 123; IVUS-BA-BMS: 142; and Angio-BA-BMS: 119). At follow-up, the IVUS-CBA-BMS group had a significantly lower restenosis rate (6.6%) than the other groups (p=0.016). We performed a quantitative coronary angiography (QCA) based matched comparison between an IVUS-guided CBA-BMS strategy (REDUCE III) and a DES strategy (Rapamycin-Eluting-Stent Evaluation At Rotterdam Cardiology Hospital, the RESEARCH study). We matched the presence of diabetes, vessel size, and lesion severity by QCA. Restenosis (>50% diameter stenosis at follow-up) and target vessel revascularisation (TVR) were examined. QCA-matched comparison resulted in 120-paired lesions. While acute gain was significantly greater in IVUS-CBA-BMS than DES (1.65±0.41 mm vs. 1.28±0.57 mm, p=0.001), late loss was significantly less with DES than with IVUS-CBA-BMS (0.03±0.42 mm vs. 0.80±0.47 mm, p=0.001). However, no difference was found in restenosis rates (IVUS-CBA-BMS: 6.6% vs. DES: 5.0%, p=0.582) and TVR (6.6% and 6.6%, respectively). An IVUS-guided CBA-BMS strategy yielded restenosis rates similar to those achieved by DES and provided an effective alternative to the use of DES.

This study investigated the machinability of titanium, two commercial titanium alloys (Ti-6Al-4V and Ti-6Al-7Nb) and free-cutting brass using the cutting temperature. The cutting temperature was estimated by measuring the thermal electromotive force of the tool-workpiece thermocouple during cutting. The thermoelectric power of each metal relative to the tool had previously been determined. The metals were slotted using a milling machine and carbide square end mills under four cutting conditions. The cutting temperatures of Ti-6Al-4V and Ti-6Al-7Nb were significantly higher than that of the titanium, while that of the free-cutting brass was lower. This result coincided with the relationship of the magnitude of the cutting forces measured in a previous study. For each metal, the cutting temperature became higher when the depth of cut or the cutting speed and feed increased. The increase in the cutting speed and feed was more influential on the value than the increase in the depth of cut when two cutting conditions with the same removal rates were compared. The results demonstrated that cutting temperature measurement can be utilized to develop a new material for dental CAD/CAM applications and to optimize the cutting conditions.

The process of cutting is analysed in fracture mechanics terms with a view to quantifying the various parameters involved. The model used is that of orthogonal cutting with a wedge removing a layer of material or chip. The behaviour of the chip is governed by its thickness and for large radii of curvature the chip is elastic and smooth cutting occurs. For smaller thicknesses, there is a transition, first to plastic bending and then to plastic shear for small thicknesses and smooth chips are formed. The governing parameters are tool geometry, which is principally the wedge angle, and the material properties of elastic modulus, yield stress and fracture toughness. Friction can also be important. It is demonstrated that the cutting process may be quantified via these parameters, which could be useful in the study of cutting in biology.

Within the sheet metal industry, different shear cutting technologies are commonly used in several processing steps, e.g. in cut to length lines, slitting lines, end cropping etc. Shearing has speed and cost advantages over competing cutting methods like laser and plasma cutting, but involves large forces on the equipment and large strains in the sheet material.Numerical models to predict forces and sheared edge geometry for different sheet metal grades and different shear parameter set-ups a...

The mechanism of remote cutting of steel plates by radiation of a high-power repetitively pulsed CO2 laser is theoretically studied. The models of melt removal by the gravity force and the recoil pressure of material vapour are proposed and the sufficient conditions for the initiation of cutting are determined. A numerical model of a thermally thin plate was employed to describe the cutting for large focal spots.

A closed form solution to the problem of steady-state wedge cutting through a ductile metal plate is presented. The considered problem is an idealization of a ship bottom raking process, i.e. a continuous cutting damage of a ship bottom by a hard knife-like rock in a grounding event. A new...

Abrasive waterjet (AWJ) cutting is a machining process to cut wide range of materials from soft materials such as rubber, leather to hard materials such as metals by means of a high-velocity slurry jet, formed as a result of injecting abrasive particles into a waterjet. The machining action is the

A hospital that is seeking ways to cut costs without compromising care should resist the temptation to lay off staff and instead make it a priority to improve efficiencies. This approach requires a formal program to identify and analyze all of the hospital's processes. The focus of the analysis should be to determine which activities are being performed efficiently, which are being performed inefficiently, and which are unnecessary. This effort will achieve the greatest success if it is customer-centric.

Experimental tests have been performed using CO 2 laser with output power 1 to 15 kW to evaluate the effect of varying the following parameters: material (carbon steel Fe 42 C, stainless steel AISI 304, concrete), laser power, beam characteristics, work piece velocity, gas type and distribution on the laser interaction zone. In the case of concrete, drilling depths of 80 mm were obtained in a few seconds using a 10 kW laser beam. Moreover pieces of 160 mm were cut at 0.01 meters per minute. Results with carbon steel indicated maximum thicknesses of 110 mm, cut at 0.01 meters per minute with 10 kW, depths about 20% lower were obtained with the AISI 304 stainless steel. A parallel investigation was aimed at characterizing particulate emission during the laser cutting process. At the end of the research it was possible to elaborate a preliminary proposal concerning a laser based dismantling system for the application to a typical Nuclear Power Station. (author)

To compare the short and long-term clinical and angiographic outcomes of drug-eluting stents (DES) versus cutting balloon angioplasty followed by bare metal stents (CBA + BMS) for the treatment of ostial lesions of the left anterior descending coronary artery (LAD). A total of 51 consecutive patients with LAD ostial lesions were treated by DES and all patients had completed 2-year clinical follow-up, 50 consecutive patients with LAD ostial lesions treated by CBA + BMS and followed up for 2 years prior to the DES era (May 2000 to November 2003) served as control group. In DES group, one patient experienced acute myocardial infarction (AMI) during hospitalization, the in-hospital major adverse cardiac event (MACE) was 1.96% (1/51), angiography follow-up data at 6-8 months were available in 29 patients and the in-DES restenosis was 10.3% (3/29), at 2-year clinical follow-up, 1 patient died, 4 patients received target lesion revascularization. Total MACE rate was 9.8% (5/51). In CBA + BMS group, there was no in-hospital death and AMI. Angiographic follow-up at 6-8 months was completed in 28 cases and in-stent restenosis rate was 17.9% (5/28). During 2-year follow-up, there was no death and AMI and 6 patients underwent target lesion revascularization. MACE rate was 12% (6/50) in this group. This study showed that both clinical and angiographic outcomes were comparable between DES and CBA + BMS treated patients with LAD ostial lesions during the 2-year follow up period.

The article deals with experimental testing of the cutting ability of exchangeable cutting inserts. Eleven types of exchangeable cutting inserts from five different manufacturers were tested. The tested cutting inserts were of the same shape and were different especially in material and coating types. The main aim was both to select a suitable test for determination of the cutting ability of exchangeable cutting inserts and to design such testing procedure that could make it possible...

Clear, concise compendium of about 150 time-saving math short-cuts features faster, easier ways to add, subtract, multiply, and divide. Each problem includes an explanation of the method. No special math ability needed.

A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

This is the second quarterly progress report for Year 3 of the ACTS project. It includes a review of progress made in: (1) Flow Loop development and (2) research tasks during the period of time between Oct 1, 2001 and Dec. 31, 2001. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 3: Addition of a Cuttings Injection/Collection System), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (e) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (f) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (g) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

This patent describes a cutting tool adapted to be positioned downhole in a well bore for removing a metal member from the well bore; a tool body adapted to be received within said well bore and to be supported at its upper end for rotation about a longitudinal axis; blades at spaced intervals on the body and extending outwardly therefrom, each of the blades having a base with a leading surface relative to the direction of rotation; closely spaced cutting elements of hard cutting material secured to said leading surface of the base in a plurality of transversely extending rows, each cutting element being of a predetermined size and shape and arranged in a predetermined generally symmetrical pattern on the base relative to the other elements, each of said cutting elements having an exposed from cutting face forming a cutting surface, a rear face secured to the leading surface of said base, a peripheral surface extending between said faces, and a relatively sharp edge formed at the juncture of the front face and peripheral surface; the front cutting face of each cutting element being arranged and constructed for directing an extending end portion of a turning cut form said member to effect a breaking of said turning from the member being cut in a predetermined manner to minimize interesting of the turning

The Quarter began with installing the new drill pipe, hooking up the new hydraulic power unit, completing the pipe rotation system (Task 4 has been completed), and making the SWACO choke operational. Detailed design and procurement work is proceeding on a system to elevate the drill-string section. The prototype Foam Generator Cell has been completed by Temco and delivered. Work is currently underway to calibrate the system. Literature review and preliminary model development for cuttings transportation with polymer foam under EPET conditions are in progress. Preparations for preliminary cuttings transport experiments with polymer foam have been completed. Two nuclear densitometers were re-calibrated. Drill pipe rotation system was tested up to 250 RPM. Water flow tests were conducted while rotating the drill pipe up to 100 RPM. The accuracy of weight measurements for cuttings in the annulus was evaluated. Additional modifications of the cuttings collection system are being considered in order to obtain the desired accurate measurement of cuttings weight in the annular test section. Cutting transport experiments with aerated fluids are being conducted at EPET, and analyses of the collected data are in progress. The printed circuit board is functioning with acceptable noise level to measure cuttings concentration at static condition using ultrasonic method. We were able to conduct several tests using a standard low pass filter to eliminate high frequency noise. We tested to verify that we can distinguish between different depths of sand in a static bed of sand. We tested with water, air and a mix of the two mediums. Major modifications to the DTF have almost been completed. A stop-flow cell is being designed for the DTF, the ACTF and Foam Generator/Viscometer which will allow us to capture bubble images without the need for ultra fast shutter speeds or microsecond flash system.

Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described.......Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described....

This report describes the work done to develop underwater plasma arc cutting techniques, to characterise aerosols from cutting operations on radioactive and non-radioactive work-pieces, and to develop suitable ventilation and filtration techniques. The work has been carried out in the framework of a contract between CEA-CEN Cadarache and the Commission of European Communities. Furthermore, this work has been carried out in close cooperation with CEA-CEN Saclay mainly for secondary emissions and radioactive analysis. The contract started in May 1986 and was completed in December 1988 by a supplementary agreement. This report has been compiled from several progress reports submitted during the work period, contains the main findings of the work and encloses the results of comparative tests on plasma arc cutting

The project`s aim is to complete development of the Radial Cutting Torch, a pyrotechnic cutter, for use in all downhole tubular cutting operations in the petroleum industry. Project objectives are to redesign and pressure test nozzle seals to increase product quality, reliability, and manufacturability; improve the mechanical anchor to increase its temperature tolerance and its ability to function in a wider variety of wellbore fluids; and redesign and pressure test the RCT nozzle for operation at pressures from 10 to 20 ksi. The proposal work statement is included in the statement of work for the grant via this reference.

The Advanced Cuttings Transport Study (ACTS) was a 5-year JIP project undertaken at the University of Tulsa (TU). The project was sponsored by the U.S. Department of Energy (DOE) and JIP member companies. The objectives of the project were: (1) to develop and construct a new research facility that would allow three-phase (gas, liquid and cuttings) flow experiments under ambient and EPET (elevated pressure and temperature) conditions, and at different angle of inclinations and drill pipe rotation speeds; (2) to conduct experiments and develop a data base for the industry and academia; and (3) to develop mechanistic models for optimization of drilling hydraulics and cuttings transport. This project consisted of research studies, flow loop construction and instrumentation development. Following a one-year period for basic flow loop construction, a proposal was submitted by TU to the DOE for a five-year project that was organized in such a manner as to provide a logical progression of research experiments as well as additions to the basic flow loop. The flow loop additions and improvements included: (1) elevated temperature capability; (2) two-phase (gas and liquid, foam etc.) capability; (3) cuttings injection and removal system; (4) drill pipe rotation system; and (5) drilling section elevation system. In parallel with the flow loop construction, hydraulics and cuttings transport studies were preformed using drilling foams and aerated muds. In addition, hydraulics and rheology of synthetic drilling fluids were investigated. The studies were performed under ambient and EPET conditions. The effects of temperature and pressure on the hydraulics and cuttings transport were investigated. Mechanistic models were developed to predict frictional pressure loss and cuttings transport in horizontal and near-horizontal configurations. Model predictions were compared with the measured data. Predominantly, model predictions show satisfactory agreements with the measured data. As a

This paper surveys the fascinating mathematics of fair division, and provides a suite of examples using basic ideas from algebra, calculus, and probability which can be used to examine and test new and sometimes complex mathematical theories and claims involving fair division. Conversely, the classical cut-and-choose and moving-knife algorithms…

Some of the diagnostic tools which are available to determine valuable reservoir rock information from drill cuttings were described. For example, valuable information can be obtained from drill cuttings and petrographic thin sections regarding mineralogy, facies, pore systems, reservoir quality and fluid sensitivity. This paper described the best ways to pick representative drill cuttings from vials. Colour and texture are among the most important determining factors. New guidelines from the Alberta Energy and Utilities Board have made it possible to obtain thin sections from drill cuttings from a competitor`s wells. Up to 12 chips from each vial can be removed for thin section scanning electron microscopy (SEM) analysis. X-ray diffraction (XRD) analysis of drill chips is not recommended because it is usually not possible to obtain enough sample material. Another powerful tool to investigate and characterize pore systems is the Mercury Injection Capillary Pressure technique. This technique makes it possible to characterize the pore system and to determine pore throat size distribution, permeability/porosity, producible reserves, capillary pressure, effective versus non-effective porosity, irreducible water saturation, and height above free water. The most reliable and valuable information is obtained from sandstone and carbonate aggregate chips in which the pore system is preserved. It was also noted that core porosity can be empirically derived if a trend line is constructed using sections prepared from an equivalent cored zone. Permeability can be derived in much the same way. 9 figs.

We introduce the simultaneous model for cake cutting (the fair allocation of a divisible good), in which agents simultaneously send messages containing a sketch of their preferences over the cake. We show that this model enables the computation of divisions that satisfy proportionality — a popular...

Copper is an essential heavy metal trace element that plays important roles in cell physiology. The Cut family was associated with the copper homeostasis and involved in several important metabolisms, such as uptake, storage, delivery, and efflux of copper. In this study, a novel Cut family cDNA was isolated from the human fetal brain library, which encodes a 273 amino acid protein with a molecular mass of about 29.3 kDa and a calculated pI of 8.17. It was named hCutC (human copper transporter protein CutC). The ORF of hCutC gene was cloned into pQE30 vector and expressed in Escherichia coli M15. The secreted hCutC protein was purified to a homogenicity of 95% by using the Ni-NTA affinity chromatography. RT-PCR analysis showed that the hCutC gene expressed extensively in human tissues. Subcellular location analysis of hCutC-EGFP fusion protein revealed that hCutC was distributed to cytoplasm of COS-7 cells, and both cytoplasm and nucleus of AD293 cells. The results suggest that hCutC may be one shuttle protein and play important roles in intracellular copper trafficking

The introduction of high power single mode fiber lasers allows for a beam of high power and a good beam quality factor (M2 ” 1.2), compared to the multimode fiber lasers often utilised in macro laser metalcutting. This paper describes fundamental studies of macro laser metalcutting with a singl...

Roadheaders are frequently used machines in mining and tunnelling, and performance prediction of roadheaders is important for project economics and stability. Several methods were proposed so far for this purpose and, rock cutting tests are the best choice. Rock cutting tests are generally divided into two groups which are namely, full scale rock cutting tests and small scale rock cutting tests. These two tests have some superiorities and deficiencies over themselves. However, in many cases, where rock sampling becomes problematic, small scale rock cutting test (core cutting test) is preferred for performance prediction, since small block samples and core samples can be conducted to rock cutting testing. Common problem for rock cutting tests are that they can be found in very limited research centres. In this study, a new mobile rock cutting testing equipment, vertical rock cutting rig (VRCR) was introduced. Standard testing procedure was conducted on seven rock samples which were the part of a former study on cutting rocks with another small scale rock cutting test. Results showed that core cutting test can be realized successfully with VRCR with the validation of paired samples t-test.

Full Text Available Plasma Arc Cutting (PAC is a thermal manufacturing process used for metal plates cutting. This work experimentally investigates the influence of process parameters onto the dimensional accuracy performance of the plasma arc cutting process. The cutting parameters studied were cutting speed (mm/min, torch standoff distance (mm, and arc voltage (volts. Linear dimensions of a rectangular workpiece were measured after PAC cutting following the full factorial design experimental approach. For each one of the three process parameters, three parameter levels were used. Analysis of means (ANOM and analysis of variances (ANOVA were performed in order for the effect of each parameter on the leaner dimensional accuracy to be assessed.

Lots of nuclear power plants have been decommissioned during the last 2 decades. An essential part of this work is the dismantling of the Reactor Pressure Vessel and its Internals. For this purpose a wide variety of different cutting technologies have been developed, adapted and applied. A detailed introduction to Plasma Arc cutting, Contact Arc Metalcutting and Abrasive Water Suspension Jet cutting is given, as it turned out that these cutting technologies are particularly suitable for these type of segmentation work. A comparison of these technologies including gaseous emissions, cutting power, manipulator requirements as well as selected design approaches are given. Process limits as well as actual limits of application are presented

Full Text Available At metal drilling, at the beginning of the process, the cutting tool in the chisel edge zone, frictions and plastically deforms the material, and then enters in cutting. If the drill is entered smoothly in cutting with a special device, its life is increased. The paper presents how the electrical current at cutting is used for the evaluation of smooth entrance in cutting in comparison with classical cutting. These are demonstrated for 41MoC11 steel drilled with a set of 30 tools having 8 mm diameter.

This article reports on the development of the cost effective abrasive cutting Sabre system which came as a result of UWG's work on the decommissioning of the Phillips' Maureen wells and adds to UWG's 'total severance solution' tools. The advantages of the system are highlighted and include the ability to operate from a platform or diving support vessel, to cut internal cases, and to eliminate the use of environmentally damaging explosives and the need to operate from a rig. The new Mark II version of the Sabre designed to work at greater depths of water, the range of the severance tools, UWG's well abandonment hole assembly system, and its aim to enter the Gulf of Mexico market are discussed. Details are given of the decommissioning of the Schwedeneck-See platforms in Kiel Bay off Germany and the Phillips' UK decommissioning plans for the Maureen platform

ACTS flow loop is now operational under elevated pressure and temperature. Currently, experiments with synthetic based drilling fluids under pressure and temperature are being conducted. Based on the analysis of Fann 70 data, empirical correlations defining the shear stress as a function of temperature, pressure and the shear rate have been developed for Petrobras synthetic drilling fluids. PVT equipment has been modified for testing Synthetic oil base drilling fluids. PVT tests with Petrobras Synthetic base mud have been conducted and results are being analyzed Foam flow experiments have been conducted and the analysis of the data has been carried out to characterize the rheology of the foam. Comparison of pressure loss prediction from the available foam hydraulic models and the test results has been made. Cuttings transport experiments in horizontal annulus section have been conducted using air, water and cuttings. Currently, cuttings transport tests in inclined test section are being conducted. Foam PVT analysis tests have been conducted. Foam stability experiments have also been conducted. Effects of salt and oil concentration on the foam stability have been investigated. Design of ACTS flow loop modification for foam and aerated mud flow has been completed. A flow loop operation procedure for conducting foam flow experiments under EPET conditions has been prepared Design of the lab-scale flow loop for dynamic foam characterization and cuttings monitoring instrumentation tests has been completed. The construction of the test loop is underway. As part of the technology transport efforts, Advisory Board Meeting with ACTS-JIP industry members has been organized on May 13, 2000.

This Quarter has been divided between running experiments and the installation of the drill-pipe rotation system. In addition, valves and piping were relocated, and three viewports were installed. Detailed design work is proceeding on a system to elevate the drill-string section. Design of the first prototype version of a Foam Generator has been finalized, and fabrication is underway. This will be used to determine the relationship between surface roughness and ''slip'' of foams at solid boundaries. Additional cups and rotors are being machined with different surface roughness. Some experiments on cuttings transport with aerated fluids have been conducted at EPET. Theoretical modeling of cuttings transport with aerated fluids is proceeding. The development of theoretical models to predict frictional pressure losses of flowing foam is in progress. The new board design for instrumentation to measure cuttings concentration is now functioning with an acceptable noise level. The ultrasonic sensors are stable up to 190 F. Static tests with sand in an annulus indicate that the system is able to distinguish between different sand concentrations. Viscometer tests with foam, generated by the Dynamic Test Facility (DTF), are continuing.

Unlike illusive magnetic field lines in vacuum, magnetic vortices in superconductors are real physical strings, which interact with the sample surface, crystal structure defects, and with each other. We address the complex and poorly understood process of vortex cutting via a comprehensive set of magneto-optic experiments which allow us to visualize vortex patterns at magnetization of a nearly twin-free YBCO crystal by crossing magnetic fields of different orientations. We observe a pronounced anisotropy in the flux dynamics under crossing fields and the filamentation of induced supercurrents associated with the staircase vortex structure expected in layered cuprates, flux cutting effects, and angular vortex instabilities predicted for anisotropic superconductors. At some field angles, we find formation of the vortex domains following a type-I phase transition in the vortex state accompanied by an abrupt change in the vortex orientation. To clarify the vortex cutting scenario we performed time-dependent Ginzburg-Landau simulations, which confirmed formation of sharp vortex fronts observed in the experiment and revealed a left-handed helical instability responsible for the rotation of vortices. This work was supported by the U.S. Department of Energy, Office of Science, Materials Sciences and Engineering Division.

The proposed research for the paper is an experimental work – measuring cutting forces and monitoring of the tool wear on the cutting edge. It compares the turning where standard roughing cycle is used and the turning where the proposed roughing cycle with variable depth of cut is applied.

Laser technology has been used in industrial processes for several decades. The most advanced development and implementation took place in laser welding and cutting of metals in automotive and ship building industries. However, there is high potential to apply laser processing to other materials in various industrial fields. One of these potential fields could be paper industry to fulfill the demand for high quality, fast and reliable cutting technology. Difficulties in industrial application of laser cutting for paper industry are associated to lack of basic information, awareness of technology and its application possibilities. Nowadays possibilities of using laser cutting for paper materials are widened and high automation level of equipment has made this technology more interesting for manufacturing processes. Promising area of laser cutting application at paper making machines is longitudinal cutting of paper web (edge trimming). There are few locations at a paper making machine where edge trimming is usually done: wet press section, calender or rewinder. Paper web is characterized with different moisture content at different points of the paper making machine. The objective of this study was to investigate the effect of moisture content of paper material on laser cutting parameters. Effect of moisture content on cellulose fibers, laser absorption and energy needed for cutting is described as well. Laser cutting tests were carried out using CO2 laser.

Full Text Available Laser technology is a convertible technology for plenty of parts in most materials. Laser material processing for industrial manufacturing applications is today a widespread procedure for welding, cutting, marking and micro machining of metal and plastic parts and components. Involvement and support this huge mass-production industry of laser cutting, new technology and dry-process using lasers were and are being actively developed. Fundamentally, industrial laser cutting or other applications on industry should satisfy the four key practical application issues including “Quality or Performance”, “Throughput or Speed”, “Cost or Total Ownership Cost”, and “Reliability”. Laser requires for examples several complicated physical factors to be resolved including die strength to be enable good wire-bonding and survival of severe cycling test, clean cutting wall surface, good cutting of direct attach film, and proper speed of cutting for achieving economy of throughput. Some example of maximum cutting rate, wherewith is normally limited laser energy, cutting speed is depend on type laser, different of cutting with one laser beam and beam pattern and applied laser power/material thickness will be introduced in this paper.

The importance of cutting fluid performance testing has increased with documentation requirements of new cutting fluid formulations based on more sustainable products, as well as cutting with minimum quantity of lubrication and dry cutting. Two sub-problems have to be solved: i) which machining...... tests feature repeatability, reproducibility and sensitivity to cutting fluids, and ii) to what extent results of one test ensure relevance to a wider set of machining situations. The present work is aimed at assessing the range of validity of the different testing methods, investigating correlation...... within the whole range of operations, materials, cutting fluids, operating conditions, etc. Cutting fluid performance was evaluated in turning, drilling, reaming and tapping, and with respect to tool life, cutting forces, chip formation and product quality (dimensional accuracy and surface integrity...

This invention relates to a method for recovering elemental silicon cutting remains containing silicon particles, wherein the method comprises manufacturing solid anodes from the cutting remains, arranging one or more manufactured anode (s) in an electrolytic cell with a molten salt electrolyte and one or more cathode (s), and applying a potential difference between the one or more anode (s) and cathode (s) to obtain an oxidation of metallic silicon in the one or more anode (s), tran...

In the automotive industry carbon fibre reinforced plastics (CFRP) are considered as a future key material to reduce the weight of the vehicle. Therefore, capable production techniques are required to process this material in mass industry. E.g., state of the art methods for cutting are limited by the high tool wear or the feasible feed rate. Laser cutting processes are still under investigation. This paper presents detailed new studies on remote laser cutting of CFRP focusing on the influence of the material properties and the quality of the cut surface. By adding light absorbing soot particles to the resin of the matrix, the cutting process is improved and fewer defects emerge.

Chemical vapor deposition (CVD) diamond coated cutting tool has excellent cutting performance, it is the most ideal tool for the processing of nonferrous metals and alloys, composites, nonmetallic materials and other difficult-to-machine materials efficiently and accurately. Depositing CVD diamond coating on the cemented carbide with high cobalt content can improve its toughness and strength, therefore, it is very important to research on the preparation technology and cu...

Apparatus for the cutting of garment patterns from one or more layers of fabric. A laser capable of producing laser light at an ultraviolet wavelength is utilized to shine light through a pattern, such as a holographic phase filter, and through a lens onto the one or more layers of fabric. The ultraviolet laser light causes rapid photochemical decomposition of the one or more layers of fabric, but only along the pattern. The balance of the fabric of the one or more layers of fabric is undamaged.

We have tested the loop elevation system. We raised the mast to approximately 25 to 30 degrees from horizontal. All went well. However, while lowering the mast, it moved laterally a couple of degrees. Upon visual inspection, severe spalling of the concrete on the face of the support pillar, and deformation of the steel support structure was observed. At this time, the facility is ready for testing in the horizontal position. A new air compressor has been received and set in place for the ACTS test loop. A new laboratory has been built near the ACTS test loop Roughened cups and rotors for the viscometer (RS300) were obtained. Rheologies of aqueous foams were measured using three different cup-rotor assemblies that have different surface roughness. The relationship between surface roughness and foam rheology was investigated. Re-calibration of nuclear densitometers has been finished. The re-calibration was also performed with 1% surfactant foam. A new cuttings injection system was installed at the bottom of the injection tower. It replaced the previous injection auger. A mechanistic model for cuttings transport with aerated mud has been developed. Cuttings transport mechanisms with aerated water at various conditions were experimentally investigated. A total of 39 tests were performed. Comparisons between the model predictions and experimental measurements show a satisfactory agreement. Results from the ultrasonic monitoring system indicated that we could distinguish between different sand levels. We also have devised ways to achieve consistency of performance by securing the sensors in the caps in exactly the same manner as long as the sensors are not removed from the caps. A preliminary test was conducted on the main flow loop at 100 gpm flow rate and 20 lb/min cuttings injection rate. The measured bed thickness using the ultrasonic method showed a satisfactory agreement with nuclear densitometer readings. Thirty different data points were collected after the test

This animation shows the view from the rear hazard avoidance cameras on the Mars Exploration Rover Spirit as the rover turns 45 degrees clockwise. This maneuver is the first step in a 3-point turn that will rotate the rover 115 degrees to face west. The rover must make this turn before rolling off the lander because airbags are blocking it from exiting from the front lander petal. Before this crucial turn took place, engineers instructed the rover to cut the final cord linking it to the lander. The turn took around 30 minutes to complete.

This animation shows the view from the front hazard avoidance cameras on the Mars Exploration Rover Spirit as the rover turns 45 degrees clockwise. This maneuver is the first step in a 3-point turn that will rotate the rover 115 degrees to face west. The rover must make this turn before rolling off the lander because airbags are blocking it from exiting off the front lander petal. Before this crucial turn could take place, engineers instructed the rover to cut the final cord linking it to the lander. The turn took around 30 minutes to complete.

The advent of affordable virtual reality (VR) displays and 360◦ video cameras has sparked an interest in bringing cinematic experiences from the screen and into VR. However, it remains uncertain whether traditional approaches to filmmaking can be directly applied to cinematic VR. Historically......’ sense of disorientation and their ability to follow the story, during exposure to fictional 360◦ films experienced using a head-mounted display. The results revealed no effects of increased cut frequency which leads us to conclude that editing need not pose a problem in relation to cinematic VR, as long...

The objective of this study was to extend the working life of cutting fluids used in metal machining operations at LLNL. The characteristics of the fluids in nine different machines were studied. The pH, bacteria level, percent coolant concentrate, percent tramp oil, and total undissolved solids were monitored on a week-to-week basis for 6 weeks. During this time, the criteria and procedures used for changing the cutting fluids in the machines were also observed. Although the study is incomplete, the following recommendations were made. Cutting fluids should be diluted with deionized water and the concentration of the cutting fluid should be monitored regularly with a refractometer. A bactericide should be added to the cutting fluid. The machines should have a thorough initial cleaning and machine oil leaks should be eliminated. Only one cutting fluid should be used throughout the shop. Methods for removing metal particles from used cutting oils should be investigated

The objective of the present work was to study the laser weldability of laser-cut 3 mm thick AISI 304 austenitic stainless steel sheet (using oxygen as an assist gas). For minimizing heat input during laser cutting, which is an important factor influencing the thickness of the oxide layer on the cut surface, laser cutting was performed in pulsed mode. The results of the study demonstrated that although the laser welding of laser-cut specimens did not result in the formation of weld defects, the resultant laser weldments exhibited reduced ductility with respect to base metal and bead-on-plate laser weldments. Laser-cut and laser-welded specimens also displayed higher notch sensitivity than the base metal. However, laser-cut and laser-welded specimens still possessed enough ductility to pass guided bend tests.

Full Text Available The paper main purpose is monitoring of tool wear in metalcutting using neural networks due to their ability of learning and adapting their self, based on experiments. Monitoring the cutting process is difficult to perform on-line because of the complexity of tool wear process, which is the most important parameter that defines the tool state at a certain moment. Most of the researches appraise the tool wear by indirect factors such as forces, consumed power, vibrations or the surface quality. In this case, it is important to combine many factors for increasing the accuracy of tool wear prediction and establish the admissible size of wear. For this, paper both the theoretical data obtained from FEM analyze and experimental ones are used and compared in order to appreciate the reliability of the results.

Full Text Available Paper concerns the comparison of functional materials parts of cutting tools used for the production of stator and rotor sheets in the electrical industry from point of view of their life. Alternatives and the properties of metal used for the production of stator and rotor components in electrical rotating machines are analysed. The main factors affecting the life of cutting tools of functional parts are analysed, one of the most important is the cutting tool functional parts material itself. Comparison of three variants of the cuttong tool funkcional parts material – 19 436 tool steel (chrome steel according to the Czech State Standard 41 9436, 19 830 high speed steel according to the Czech State Standard 41 9830 and a special powder metallurgy product – ledeburite tool steel Vanadis 10. Useful lifes of the functional components of individual cutting tools performances can be calculated from the theoretical lifes by their multiplying the coefficients of the tool design and the cutting edges shape complexity.

The laser has given manufacturing industry a new tool. When the laser beam is focused it can generate one of the world's most intense energy sources, more intense than flames and arcs, though similar to an electron beam. In fact the intensity is such that it can vaporise most known materials. The laser material processing industry has been growing swiftly as the quality, speed and new manufacturing possibilities become better understood. In the fore of these new technologies is the process of laser cutting. Laser cutting leads because it is a direct process substitu­ tion and the laser can usually do the job with greater flexibility, speed and quality than its competitors. However, to achieve these high speeds with high quality con­ siderable know how and experience is required. This information is usually carefully guarded by the businesses concerned and has to be gained by hard experience and technical understanding. Yet in this book John Powell explains in lucid and almost non­ technical language many o...

For standard leptogenesis from the decay of singlet right-handed neutrinos, we derive source terms for the lepton asymmetry that are present in a finite density background but absent in the vacuum. These arise from cuts through the vertex correction to the decay asymmetry, where in the loop either the Higgs boson and the right-handed neutrino or the left-handed lepton and the right-handed neutrino are simultaneously on-shell. We evaluate the source terms numerically and use them to calculate the lepton asymmetry for illustrative points in parameter space, where we consider only two right-handed neutrinos for simplicity. Compared to calculations where only the standard cut through the propagators of left-handed lepton and Higgs boson is included, sizable corrections arise when the masses of the right-handed neutrinos are of the same order, but the new sources are found to be most relevant when the decaying right-handed neutrino is heavier than the one in the loop. In that situation, they can yield the dominant contribution to the lepton asymmetry.

Full Text Available Nickel-based superalloys such as Waspaloy are used for engine components and in the nuclear industry, where considerable strength and corrosion resistance at high operating temperatures are called for. These characteristics of such alloys cause increases in cutting temperature and resultant tool damage, even at low cutting speeds and low feed rates. Thus, they are classified as difficult-to-cut materials. This article presents a cooling method to be used in metalcutting based on a tool holder with a closed internal cooling system with cooling fluid circulating inside. Hence, a green cooling method that does not harm the environment and is efficient in removing heat from the cutting zone was developed. A series of cutting experiments were conducted to investigate the practicality and effectiveness of the internally cooled tool model. The developed system achieved up to 13% better surface quality than with dry machining, and tool life was extended by 12%. The results clearly showed that with the reduced cutting temperature of the internal cooling, it was possible to control the temperature and thus prevent reaching the critical cutting temperature during the turning process, which is vitally important in extending tool life during the processing of Waspaloy.

- to long-term governance arrangements. It finds that although industry interviewees agreed PPP governance had improved significantly, they had differing views on how capable Australian states were in governing PPP and how well this task was being undertaken. They were also split on the adequacy......Much attention has gone towards ‘up-front’ processes when delivering infrastructure public–private partnerships (PPPs), but less on how to best govern after the ribbon is cut and the infrastructure built. This paper identifies the primary contractual and institutional governance challenges arising...... in the medium to long term of PPP concession contracts and explores these governance challenges through interviews with high-level PPP industry insiders. The paper presents new findings on the importance of good public administration for successful PPP operation, and on the interesting evolution of medium...

After having recalled the interest of cut-off practices when consumption is higher than production (a cut-off operator turns out some sources of consumption), this publication more particularly addresses the practice of cut-off in the residential sector, also called diffused cut-off. This practice is based on a temporary reduction of electricity consumption in a great number of small sites (for example, a brief interruption of the electricity supply of radiators, hot water tanks, air conditioning devices in dwellings to reduce the total demand of an area). The three main modalities of valorisation of this cut-off power by the operator are presented. Advantages and drawbacks are discussed, and more particularly the impact of cut-off on thermal comfort

Electrolyte with high electric current localization, containing 1-3 % KOH and 2-10 % NH 3 , is suggested to use for electrochemical cutting of tungsten. A cutting device is described which includes a cathode feed mechanism based on electric heating and a circuit of automatic control of an interelectrode gap. Laue patterns obtained from a cut surface are practically the same as ones from the initial monocrystal

Full Text Available In this paper; in general potential developments and trends of a particular machining field by extensively evaluating present studies of laser beam machining have been discussed. As it is indicated below, technical literatures have been subsumed under five major headlines: Experimental studies, reviews, optimization researches of the cutting parameters, theoretical modelling studies of laser beam cutting and academic studies relating to laser cutting

Cemented carbide (hard metal) cutting tools are the first choice to machine hard materials or to conduct high performance cutting processes. Main advantages of cemented carbide cutting tools are their high wear resistance (hardness) and good high temperature strength. In contrast, cemented carbide cutting tools are characterized by a low toughness and generate higher production costs, especially due to limited resources. Usually, cemented carbide cutting tools are produced by means of powder metallurgical processes. Compared to conventional manufacturing routes, these processes are more expensive and only a limited number of geometries can be realized. Furthermore, post-processing and preparing the cutting edges in order to achieve high performance tools is often required. In the present paper, an alternative method to substitute solid cemented carbide cutting tools is presented. Cutting tools made of conventional high speed steels (HSS) were coated with thick WC-Co (88/12) layers by means of thermal spraying (HVOF). The challenge is to obtain a dense, homogenous, and near-net-shape coating on the flanks and the cutting edge. For this purpose, different coating strategies were realized using an industrial robot. The coating properties were subsequently investigated. After this initial step, the surfaces of the cutting tools were ground and selected cutting edges were prepared by means of wet abrasive jet machining to achieve a smooth and round micro shape. Machining tests were conducted with these coated, ground and prepared cutting tools. The occurring wear phenomena were analyzed and compared to conventional HSS cutting tools. Overall, the results of the experiments proved that the coating withstands mechanical stresses during machining. In the conducted experiments, the coated cutting tools showed less wear than conventional HSS cutting tools. With respect to the initial wear resistance, additional benefits can be obtained by preparing the cutting edge by means

Oct 16, 2013 ... This growing concern about contamination with cutting fluids makes remediation process imperative. White rot fungus, Pleurotus pulmonarius was investigated in this pilot study for its potential to bioremediate contaminants such as heavy metals and total petroleum hydrocarbon at 10, 20 and 30%.

Contamination of soil with industrial cutting fluids containing heavy metals and petroleum hydrocarbons has detrimental effects on ecosystems. As such contaminants constitute risk to human health; they can enter the food chain through agricultural products or contaminated drinking water. This growing concern about ...

ABSTRACT: Vegetable oils (palm oil, groundnut oil, shear butter oil and cotton seed oil) have been used as lubricants in the turning operation of aluminum under varying spindle speeds, feed rates and depths of cut and the results compared with kerosene (due to the gummy nature of aluminium metal). The parameters ...

Vegetable oils (palm oil, groundnut oil, shear butter oil and cotton seed oil) have been used as lubricants in the turning operation of aluminum under varying spindle speeds, feed rates and depths of cut and the results compared with kerosene (due to the gummy nature of aluminium metal). The parameters investigated are ...

Over the last few years laser cutting has been widely introduced in industrial production lines, mainly due to the high processing speeds. In the present work a fundamental aspect of the cutting process of metals has been considered: the formation of periodic striations on the cut edge that greatly affects the quality of the treated samples. Therefore this paper is devoted to the study of the roughness of the cut surfaces with a particular attention to the dependence of this parameters on the working conditions. For a better understanding of the variables involved in the process, a comparison of the experimental data with the results of an analytical model has been performed. Furthermore a real time monitoring of the infrared emission coming from the interaction zone has been carried out by means of an electrooptic device properly developed for the measurements of the local temperature. A correlation between these data and the roughness measurements has been found.

Today major metalcutting companies in industrial countries, looking to gain time and reduce manufacturing costs while respecting the environment. There are many phenomena which affect the quality and production costs of the product, including cutting efforts, cutting temperature, residual stresses, etc. A better understanding of these phenomena will reduce production costs and maximize productivity. The aim of this work is to analyze the effect of machining conditions (cutting speed, feed speed and cutting depth) on cutting temperature and residual stresses, during the milling operations using the response surface method. A good accuracy between predicted and measured values of the cutting temperature was found, the cutting speed and the depth of cut are parameters whose effect is most sensitive to the residual stresses and the cutting temperature.However, little influence has been registered in the case of an increase of the feed rate. The percentage of error is 4.57%, indicating that the numerical approach can accurately predict the cutting temperature of the AISI 1045.

Fluidyne Corporation has developed a unique process and apparatus that allow selected abrasives to be introduced into high-speed waterjet to produce abrasive-entrained waterjet that has high material-cutting capabilities, which is termed by Fluidyne as the Abrasion Jet. Such Abrasion Jet has demonstrated capability in cutting hard rock and concrete at a modest pressure of less than 1360 bars (20,000 psi) and a power input of less than 45 kW (60 horsepower). Abrasion Jet cutting of concrete is characterized by its high rate of cutting, flexible operation, good cut quality, and relatively low costs. This paper presents a general description of this technology together with discussions of recent test results and how it could be applied to nuclear decontamination and decommissioning work. 8 references

Processes of cutting stainless steel by ytterbium fibre and CO 2 lasers have been experimentally compared. The cut surface roughnesses for 3- and 5-mm-thick stainless steel sheets are determined. The absorption coefficient of laser radiation during cutting is measured. It is established that the power absorbed by metal during cutting by the CO 2 laser exceeds that for the ytterbium laser (provided that the cutting speed remains the same). The fact that the maximum cutting speed of the CO 2 laser is lower than that of the ytterbium fibre laser is explained. (laser technologies)

The trend toward downsizing of engines helps to increase the number of turbochargers around Europe. As for the turbocharger, the temperature of the exhaust gas is so high that the parts made of nickel base super alloy Inconel 713C are used as high temperature strength metals. External turning of Inconel 713C which is used as the actual automotive parts was carried out. The effect of the cutting fluids and cutting conditions on the surface integrity and tool wear was investigated, considering global environment and cost performance. As a result, in the range of the cutting conditions used this time, when the depth of cut was small, the good surface integrity and tool life were obtained. However, in the case of the large corner radius, it was found that the more the cutting length increased, the more the tool wear increased. When the cutting length is so large, the surface integrity and tool life got worse. As for the cutting fluids, it was found that the synthetic type showed better performance in the surface integrity and tool life than the conventional emulsion. However, it was clear that the large corner radius made the surface roughness and tool life good, but it affected the size error etc. in machining the workpiece held in a cantilever style.

It is shown that cutting quasi-emf measured under the contact interaction of a number of pure metals (molybdenum, titanium, niobium, iron, copper, beryllium, lead, nickel and cobalt), graphite and silicon correlates closely with Fermi levels calculated for them, i.e. it reflects the potential electron energy. Correlation is observed at different cutting rate (temperature) and consequently at different electron kinetic energy

A closed form solution to the problem of steady state wedge cutting through a ductile metal plate is presented. The considered problem is an idealization of a ship bottom raking process, i.e. a continuous cutting damage of a ship bottom by a hard knife-like rock in a grounding event. A new...

Full Text Available The results of interviews suggest that majority of the cut flowers’ consumers has favourite kind of flower, among which most frequently pointed one was the rose. More than half of the interviewed favour the uniform colour of cut flowers and red colour was the most favourite one. The subtle smell of flowers was the most preferable one but the intensive fragrance was favoured for more consumers than odourless flowers. The data from selected florists’ confirm the information from interviews – in spite of the occasion, roses were the most demanded cut flowers.

An investigation has been conducted of the use of laser energy for cutting contours, diameters, and holes in flat and shaped Kevlar 49 fiber-reinforced epoxy laminates as an alternate to conventional machining. The investigation has shown that flat laminates 6.35 mm thick may be cut without backup by using a high-powered (1000-watt) continuous wave CO/sub 2/ laser at high feedrates (33.87 mm per second). The cut produced was free of the burrs and delaminations resulting from conventional machining methods without intimate contact backup. In addition, the process cycle time was greatly reduced.

The contribution of Regge cuts to single-particle inclusive processes is analyzed using the techniques of Gribov. The dependence of these contributions on the polarization state of the target is emphasized. A general formula is obtained and certain contributions to it are calculated. It is not possible, however, to reduce this to a simple, powerful formula expressing the total cut contribution in terms of other measurable quantities, as can be done for the cut contribution to the total cross section. The reasons for this are discussed in detail. The single-particle intermediate states, analogous to the absorption model for elastic scattering, are explicitly calculated as an illustration

Lawrence Livermore National Laboratory (LLNL) examined the waste stream from a water jet cutting operation, to evaluate the possible reuse of waste garnet sand. The sand is a cutting agent used to shape a variety of materials, including metals. Nearly 70,000 pounds of waste sand is generated annually by the cutting operation. The Environmental Protection Department evaluated two potential reuses for the spent garnet sand: backfill in utility trenches; and as a concrete constituent. In both applications, garnet waste would replace the sand formerly purchased by LLNL for these purposes. Findings supported the reuse of waste garnet sand in concrete, but disqualified its proposed application as trench backfill. Waste sand stabilized in a concrete matrix appeared to present no metals-leaching hazard; however, unconsolidated sand in trenches could potentially leach metals in concentrations high enough to threaten ground water quality. A technical report submitted to the San Francisco Bay Regional Water Quality Control Board was reviewed and accepted by that body. Reuse of waste garnet cutting sand as a constituent in concrete poured to form walkways and patios at LLNL was approved

Air bubbles generated upon cutting incore structural materials are passed through a lattice-like metal mesh to be divided finely, and then risen in pool water. The air bubbles are risen in a state where fine metal particles are contained in a carrier gas upon conducting a plasma cutting operation. The fine particles in the air bubbles are moved to the surface of the bubbles by the effect of diffusion, inertia and gravitational precipitation, and transferred to water and removed. Since the diameter of the air bubbles is decreased, the time for the transfer of the particles to the surface of the air bubbles can be shortened to increase the amount of particles transferred per time and improve the collecting efficiency. Since fine particles of radioactive metals generated upon cutting can be collected by dividing air bubbles finely, the ventilation system of an operation chamber can be simplified. In addition, cutting operation at a shallow water depth is enabled to thereby increase the degree of freedom for operations. (N.H.)

A comprehensive study of the drill cuttings pile at North West Hutton was undertaken in August, 1992. Fifty one wells have been drilled in the field, mainly using mineral oil based drill fluids, with the cuttings discharged to sea. The cuttings pile was mapped using a 3D side scan sonar system and the periphery was defined by towed side scan sonar and gamma ray spectrometer surveys. The pile was cored by vibrocorer to a maximum depth of 2.35m. The cores were assessed geotechnically and subsampled for physical and chemical analyses. Environmental impact was investigated by grab sampling at 12 stations out to 7,500m, selected on the basis of cuttings distribution. The results are relevant to the corrosion and long-term environmental effects of oily cuttings piles, the remove/leave alone debate, and abandonment planning. The cores were subsampled for hydrocarbon, trace metals and sulphide content and grain size analysis. Metals analyses included identification of metal species to estimate bioavailability and implications of pile disturbance. Estimates of oil migration within the pile are made from correlation of the chemical analyses results with the drilling history, in particular the change from diesel to low toxicity base oil in 1984. Strong gradients were found in the faunal data which correlate well with the physical and chemical results. Dense populations of opportunists species were present adjacent to the platform, including a novel molluscan opportunist. This is the first comprehensive study of an oily cuttings pile and is a contribution to the debate on their long term impact and fate on abandonment

The results of interviews suggest that majority of the cut flowers’ consumers has favourite kind of flower, among which most frequently pointed one was the rose. More than half of the interviewed favour the uniform colour of cut flowers and red colour was the most favourite one. The subtle smell of flowers was the most preferable one but the intensive fragrance was favoured for more consumers than odourless flowers. The data from selected florists’ confirm the information from interviews – in...

To establish a method of determining the machinability of dental materials for CAD/CAM systems, the machinability of titanium, two titanium alloys (Ti-6Al-4V and Ti-6Al-7Nb), and free-cutting brass was evaluated through cutting force and spindle motor current. The metals were slotted using a milling machine and square end mills at four cutting conditions. Both the static and dynamic components of the cutting force represented well the machinability of the metals tested: the machinability of Ti-6Al-4V and Ti-6Al-7Nb was worse than that of titanium, while that of free-cutting brass was better. On the other hand, the results indicated that the spindle motor current was not sensitive enough to detect the material difference among the titanium and its alloys.

Full Text Available Este trabalho busca otimizar o planejamento do processo de corte unidimensional de tubos estruturais metálicos utilizados na fabricação de aeronaves leves agrícolas. Dois modelos de programação linear inteira mista são apresentados com o objetivo de minimizar as perdas do material cortado e considerando a possibilidade de gerar sobras com tamanhos suficientes para reaproveitamento (retalhos. Os modelos são resolvidos por meio de uma linguagem de modelagem usando um software de otimização. Para a validação dos modelos, dois experimentos computacionais foram realizados com dados reais de uma carteira de pedidos de uma aeronave leve voltada para o segmento do mercado agrícola, o Ipanema, produzido pela empresa brasileira Neiva/Embraer. As soluções dos modelos são comparadas com as soluções de uma heurística residual de arredondamento guloso da literatura e também com as soluções utilizadas pela empresa. Os resultados mostram que os modelos são úteis para apoiar as decisões envolvidas no planejamento deste processo de corte.This study aims to optimize the one-dimensional cutting process planning of structural metallic tubes used to build agricultural light aircrafts. Two mixed integer linear programming models are presented to minimize the waste of material cut and considering the possibility of generating surpluses with sizes sufficiently large for reuse (leftovers. The models are solved using a commercial modeling language and an optimization solver. For the validation of the models, two computational experiments were performed with actual data from the portfolio of a light aircraft designed for agricultural purposes, the Ipanema, produced by the Brazilian company Neiva/Embraer. The solutions of the models are compared with the solutions of a constructive heuristic of the literature and the solutions used by the company. The results show that the models are useful for being used in the planning of this cutting process.

Full Text Available Even though the body of literature in the area of cutting and packing is growing rapidly, research seems to focus on standard problems in the first place, while practical aspects are less frequently dealt with. This is particularly true for setup processes which arise in industrial cutting processes whenever a new cutting pattern is started (i.e. a pattern is different from its predecessor and the cutting equipment has to be prepared in order to meet the technological requirements of the new pattern. Setups involve the consumption of resources and the loss of production time capacity. Therefore, consequences of this kind must explicitly be taken into account for the planning and control of industrial cutting processes. This results in extensions to traditional models which will be reviewed here. We show how setups can be represented in such models, and we report on the algorithms which have been suggested for the determination of solutions of the respective models. We discuss the value of these approaches and finally point out potential directions of future research.

The effects of cutting speed and assist gas pressure on laser cutting of 1-mm thick Al 1050, AZ31, and Ti6Al4V lightweight alloys are experimentally investigated. Fiber laser cutting of these materials is not broadly investigated and the acquisition of a new level of knowledge is of fundamental importance for applications like sheet metal trimming in automotive industry. The main process outputs are in depth compared with results reported in literature and obtained by cutting with CO2 and Nd∶YAG lasers. The good cut quality, the high productivity, and the easy delivery of the beam obtained at the same time, corroborate the advantage of using fiber lasers for thin sheets lightweight alloys cutting.

The cutting of unidirectional CFRP, perpendicular as well as parallel to the fibre orientation, is examined. Shaping experiments, ‘quick-stop’ experiments, and a new chip preparation technique are used for the investigation. The formation of the chips, and the quality of the machined surface...

Cake cutting is a fundamental model in fair division; it represents the problem of fairly allocating a heterogeneous divisible good among agents with different preferences. The central criteria of fairness are proportionality and envy-freeness, and many of the existing protocols are designed...... of the simplest and most elegant continuous algorithms -- the Dubins-Spanier procedure, which guarantees a proportional allocation of the cake -- and study its equilibria when the agents use simple threshold strategies. We show that given a cake cutting instance with strictly positive value density functions...

Full Text Available The present approach to capacity planning in operations producing heavy metal shapes causes problems in fulfilling the required financial and volume indexes in production, as well as in meeting the work order completion dates. The article represents the methodology for optimal production scheduling in operations producing heavy plate cut shapes, which significantly eliminates the above-mentioned problems. The methodology is based on the application Generalized Assignment Problem (GAP.

In spite of the manifold efforts to reach a total renouncement of the use of cooling lubricants in metalcutting for environmentally reasons, cooling lubrication is an essential condition to achieve an economical tool life and the required surface quality in many cases. Against this background, the minimum quantity cooling lubrication is an interesting possibility for an economical and environmentally compatible production which combines the functionality of the cooling lubrication with an ex...

This article presents a lesson that allows students to make bird ornaments using a metal tooling as it can be textured, cut, and colored. In this lesson, students choose a bird and sketch it on a piece of paper. Once the sketches are complete, students copy their pictures on a second piece of paper by taping the sketch over a sheet of blank paper…

Aluminium (2.7 g/cm 3 ) and magnesium (1.7 g/cm 3 ) are two competing light metals with similar mechanical properties and excellent possibilities for recycling. The forming of magnesium is often seen as an impediment to its use. New forming techniques using magnesium shavings are being developed, particularly in Japan. The machining of magnesium alloys by removal of metal raises safety concerns (risk of fire), which limits many potential applications of magnesium. The purpose of this work is to clarify and compare the machining properties of these two types of metal and better understand the mechanisms that may explain the differences in behaviour. Such a comparison could eventually provide an estimate of the cost of producing shavings for the manufacture of aluminium and magnesium parts through forging and extrusion, which would limit environmental pollution. Based on an analysis of cutting resistance during machining, it was demonstrated that magnesium alloys are easier to machine than similar aluminium alloys. Magnesium shavings are shorter than those of 6061-T6, but are especially more regular than those of A356, and their size is independent of cutting speed. It was also demonstrated that the fragility of materials can be characterized based on the results of cutting resistance produced during drilling

Minimum normalised graph cuts are highly effective ways of partitioning unlabeled data, having been made popular by the success of spectral clustering. This work presents a novel method for learning hyperplane separators which minimise this graph cut objective, when data are embedded in Euclidean space. The optimisation problem associated with the proposed method can be formulated as a sequence of univariate subproblems, in which the optimal hyperplane orthogonal to a given vector is determined. These subproblems can be solved in log-linear time, by exploiting the trivial factorisation of the exponential function. Experimentation suggests that the empirical runtime of the overall algorithm is also log-linear in the number of data. Asymptotic properties of the minimum cut hyperplane, both for a finite sample, and for an increasing sample assumed to arise from an underlying probability distribution are discussed. In the finite sample case the minimum cut hyperplane converges to the maximum margin hyperplane as the scaling parameter is reduced to zero. Applying the proposed methodology, both for fixed scaling, and the large margin asymptotes, is shown to produce high quality clustering models in comparison with state-of-the-art clustering algorithms in experiments using a large collection of benchmark datasets.

... some relaxing yoga exercises Things to Help You Express the Pain and Deep Emotion Some people cut because the emotions that they ... may be hard for them to recognize these emotions for what they are — like anger, ... songs or poetry to express what you're feeling listen to music that ...

A number of “big-science” projects in Brazil could be hit if the government pushes through a 44% cut to the R5bn (£1.28bn) budget of the Ministry of Science, Technology, Innovations and Communications (MCTIC).

In a time of educational budget cuts, the arts seem to take the major brunt of the financial ax. Fine arts programs are often pitted against one another for survival. The music industry and supporting corporations, such as American Express, campaign to have instruments donated or purchased to keep educational programs alive. The visual arts do not…

Accidental power cuts - a permanent nuisance when running accelerators or computing services, since it takes a lot of time to recover from them. While I feel very sorry for those who are under pressure to get their service running again and deeply regret the loss of down-time and availability, I must admit that I like power cuts: power cuts make computers reboot! And rebooting computers at CERN means all the pending software patches are automatically applied. But don’t think I am egotistic enough to endorse power cuts. Not necessarily! I am already happy if you regularly patch your computer(s) yourself, where regularly means at least once a month: · If you run a centrally or locally managed Windows computer, give that small orange blinking “CMF” icon in the taskbar a chance in the evening to apply all the pending patches. Also, let it initiate a reboot at the end! · If you have a personal computer with your own Windows operating system, ...

There are more uses for a turkey than roasting it whole for holiday occasions. The least expensive way to have turkey pieces, especially if the turkey is purchased on sale, is to cut it up yourself. The following is to serve as a butchering and processing guide.

Elliptical vibration cutting (EVC) has been widely concerned since it was proposed, and its unique characteristics such as friction reversal and intermittent cutting can effectively extend the tool life, improve the machined surface roughness and so on. The objective of this paper was to predict the behavior of cutting force. A method of predicting the behavior of cutting force based on the chip thickness under various cutting conditions is proposed. Based on the established tool motion model, the chip model was founded. By numerical simulation, the effects of cutting parameters on cutting force under various cutting conditions were studied. The results show that the chip thickness can be used to predict the behavior of cutting force.

Paper presents the results of changes in the three components of cutting forces of paper stacks cutting during the cutting cycle in single-knife guillotine. The changes of the three components of cutting force at different stages of cutting cycle were analyzed.

To generally improve effectivity of parts production and metalcutting process, there are used process models of super alloys together with finite element modeling simulations. Advanced measurement methods of the process could improve and verify the accuracy of these models. These methods cause many error sources when using empiric or exact methods such as infrared radiation thermography to measure the temperature distribution of the tool, workpiece, and chip during metalcutting. Measuring of metal machining is challenging due to factors such as the high magnification required, high surface speeds and deformations, micro-blackbody effects, changing emissivity and deformations present at metalcutting. As part of an ongoing effort to improve our understanding of uncertainties associated with these measurement methods, multimeasurement sets of experiments were performed. First set of measurements observed connection between surface temperature and the internal temperature of the cutting tool. This was accomplished by measuring the temperature using a thermal camera in cutting zone. Second set performed high-speed scan of dynamic processes such as formation of elastic and plastic deformation. During this operation was applied high-speed scannning system using macro conversion lens for monitoring of micro-structural changes in deformation areas. Next necessary applied set is recording of dynamic processes by implementation of piezoelectric measurement device for monitoring of cutting forces. The outputs from multimeasuring system are the basis for verification of theoretical knowledge from this field and elimination of uncertainties, which arise by using computer simulation systems.

In nuclear facilities there exist, besides relatively simple components, such as vessels and piping, numerous complex components including the multilayered plate with water layer in between, a bunch of thin tubes and composite lamination of dissimilar materials like metal/non-metal. In conventional development of reactor dismantling technology, the technology development has been made mainly for remote cutting of thick-walled structures like the reactor pressure vessel and the reactor internals. These techniques, however, are not always suitable in cutting the above-mentioned structures. As means of cutting such structures efficiently, these is available the abrasion water-jet cutting technology. This technology is now drawing attention for cutting or shaping new materials like composite material and ceramics in high precision and high efficiency. In the present report by way of its feasibility in nuclear facilities decommissioning the following are described. Principle and features of the water-jet cutting technology, system con-figuration, cutting or shaping performance, and some examples of the cutting and shaping. (author)

Resistance projection welding is described pointing out the advantages, the machine requirements to be met, the suitability of various metals and/or metal combinations, the design considerations, the projection design requirements and their placement, and the limitations of this process

... depression, bipolar disorder , eating disorders, obsessive thinking, or compulsive behaviors. It can also be a sign of mental ... can be habit forming. It can become a compulsive behavior — meaning that the more a person does it, ...

Provided in some embodiments is a method of manufacturing a pipe conformable water-cut sensors system. Provided in some embodiments is method for manufacturing a water-cut sensor system that includes providing a helical T-resonator, a helical ground conductor, and a separator at an exterior of a cylindrical pipe. The helical T-resonator including a feed line, and a helical open shunt stub conductively coupled to the feed line. The helical ground conductor including a helical ground plane opposite the helical open shunt stub and a ground ring conductively coupled to the helical ground plane. The feed line overlapping at least a portion of the ground ring, and the separator disposed between the feed line and the portion of the ground ring overlapped by the feed line to electrically isolate the helical T-resonator from the helical ground conductor.

Full Text Available Management of thermo-physical process of cutting zone by changing certain parameters of the cutting regime, tool geometry or coolant using allows to achieve a higher level of handling performance. The forecasting of thermal processes during metalcutting is characterized by the multifactor of the model and the nonlinearity of the connection between the temperature field of the cutting zone and the processing parameters. Therefore realistic modeling of these processes with regard to the maximum number of influencing factors which will minimize the time and cost of experimental studies is very important. The research investigates the use of computer-aided design SolidWorks Simulation system to analyze the thermal processes occurring in the cutting zone during finishing turning of hardened circular steel cutting blade of superhard material. While modeling, the distribution of heat generated in cut (in the zone of plastic deformation of the workpiece and on the surfaces of friction of the cutting blade with chips and the treated surface is observed by four flows: to the tool, chips, workpiece and the environment. The limiting conditions for the existence of the developed model-geometric, physical and temporal limits are defined. Simulation is performed in steady and transient modes. Control of adequacy of simulation results is made. The conclusions of the analysis of opportunities of CAD SolidWorks Simulation System for research of thermal processes the cutting zone are drawn.

Full Text Available A novel parabolic trough concentrating solar heating for cut tobacco drying system was established. The opening width effect of V type metal cavity absorber was investigated. A cut tobacco drying mathematical model calculated by fourth-order Runge-Kutta numerical solution method was used to simulate the cut tobacco drying process. And finally the orthogonal test method was used to optimize the parameters of cut tobacco drying process. The result shows that the heating rate, acquisition factor, and collector system efficiency increase with increasing the opening width of the absorber. The simulation results are in good agreement with experimental data for cut tobacco drying process. The relative errors between simulated and experimental values are less than 8%, indicating that this mathematical model is accurate for the cut tobacco airflow drying process. The optimum preparation conditions are an inlet airflow velocity of 15 m/s, an initial cut tobacco moisture content of 26%, and an inlet airflow temperature of 200°C. The thermal efficiency of the dryer and the final cut tobacco moisture content are 66.32% and 14.15%, respectively. The result shows that this parabolic trough concentrating solar heating will be one of the heat recourse candidates for cut tobacco drying system.

This paper is focused on 3D computer simulation of cutting processes for brittle materials and silicon wafers. Computer-aided analysis of wafer scribing and dicing is carried out with the use of the ANSYS CAE (computer-aided engineering) software, and a parametric model of the processes is created by means of the internal ANSYS APDL programming language. Different types of tool tip geometry are analyzed to obtain internal stresses, such as a four-sided pyramid with an included angle of 120° and a tool inclination angle to the normal axis of 15°. The quality of the workpieces after cutting is studied by optical microscopy to verify the FE (finite-element) model. The disruption of the material structure during scribing occurs near the scratch and propagates into the wafer or over its surface at a short range. The deformation area along the scratch looks like a ragged band, but the stress width is rather low. The theory of cutting brittle semiconductor and optical materials is developed on the basis of the advanced theory of metal turning. The fall of stress intensity along the normal on the way from the tip point to the scribe line can be predicted using the developed theory and with the verified FE model. The crystal quality and dimensions of defects are determined by the mechanics of scratching, which depends on the shape of the diamond tip, the scratching direction, the velocity of the cutting tool and applied force loads. The disunity is a rate-sensitive process, and it depends on the cutting thickness. The application of numerical techniques, such as FE analysis, to cutting problems enhances understanding and promotes the further development of existing machining technologies.

Germany's 1997 budget contains cuts amounting to 3.7% in funding of domestic research programs and in contributions to international labs. Contributions will be cut to the European Space Agency, the European Synchrotron facility and CERN.

Lubricants known as cutting fluids are used in the metal-mechanic industry with the function of cooling and lubricating the cutting zone. These lubricants normally have a water phase, an oil phase, emulsifying agents and additives. Once the operational capacity of these fluids has ceased, either due to biological deterioration or to overabundance of contaminants, the emulsions being used must be treated in order to adequate their effluents for discharge. This study aims to evaluate the destab...

Grinding operations are very significant among the manufacturing processes of the metal-mechanic industry. In conventional grinding, cutting fluids are of great concern for improving productivity, but also for being hazardous to the environment. In order to contribute to the knowledge of the actual toxic effects of these products in aquatic environments, the present work assesses the toxicity potential through acute toxicity tests of three different kinds of cutting fluids, with three differe...

Machining of Metal Matrix Composites (MMCs) is very significant process and has been a main problem that draws many researchers to investigate the characteristics of MMCs during different machining process. The poor machining properties of hard particles reinforced MMCs make drilling process a rather interesting task. Unlike drilling of conventional materials, many problems can be seriously encountered during drilling of MMCs, such as tool wear and cutting forces. Cutting tool wear is a very ...

Cut marks on bones provide crucial information about tools used and their mode of application, both in archaeological and forensic contexts. Despite a substantial amount of research on cut mark analysis and the influence of fire on bones (shrinkage, fracture pattern, recrystallisation), there is still a lack of knowledge in cut mark analysis on burnt remains. This study provides information about heat alteration of cut marks and whether consistent features can be observed that allow direct in...

Full Text Available We report on an optical sensor system attached to a 4 kW fiber laser cutting machine to detect cutting interruptions. The sensor records the thermal radiation from the process zone with a modified ring mirror and optical filter arrangement, which is placed between the cutting head and the collimator. The process radiation is sensed by a Si and InGaAs diode combination with the detected signals being digitalized with 20 kHz. To demonstrate the function of the sensor, signals arising during fusion cutting of 1 mm stainless steel and mild steel with and without cutting interruptions are evaluated and typical signatures derived. In the recorded signals the piercing process, the laser switch on and switch off point and waiting period are clearly resolved. To identify the cutting interruption, the signals of both Si and InGaAs diodes are high pass filtered and the signal fluctuation ranges being subsequently calculated. Introducing a correction factor, we identify that only in case of a cutting interruption the fluctuation range of the Si diode exceeds the InGaAs diode. This characteristic signature was successfully used to detect 80 cutting interruptions of 83 incomplete cuts (alpha error 3.6% and system recorded no cutting interruption from 110 faultless cuts (beta error of 0. This particularly high detection rate in combination with the easy integration of the sensor, highlight its potential for cutting interruption detection in industrial applications.

Until now all studies on the role of air emboli in the water uptake of cut flowers describe indirect methods to demonstrate the presencFe of air in the plant tissues. Using cut chrysanthemum flowers, this report is the first one that directly visualises both air and water in xylem ducts of cut

Friction Stir Welding (FSW) is a relatively new industrial process that was invented at The Weld Institute (TWI, United Kingdom) and patented in 1992 under research funded by in part by the National Aeronautics and Space Administration (NASA). Often quoted advantages of the process include good strength and ductility along with minimization of residual stress and distortion. Less well advertised are the beneficial effects of this solid state welding process in the field of occupational and environmental safety. It produces superior weld products in difficult to weld materials without producing any toxic fumes or solid waste that must be controlled as hazardous waste. In fact, it reduces noise pollution in the workspace as well. In the early days of FSW, most welding was performed on modified machine tools, in particular on milling machines with modified milling cutters. In spite of the obvious milling heritage of the process, the techniques and lessons learned from almost 250 years of successful metalworking with milling machines have not been applied in the field of modern Friction Stir Welding. The goal of the current research was to study currently successful FSW tools and parameterize the process in such a way that the design of new tools for new materials could be accelerated. Along the way, several successful new tooling designs were developed for current issues at the Marshall Space Flight Center with accompanying patent disclosures

NASA is advancing a new development approach and new technologies in the design construction, and testing of the next great launch vehicle for space exploration. The ability to use these new tools is made possible by a learning culture able to embrace innovation, flexibility, and prudent risk tolerance, while retaining the hard-won lessons learned through the successes and failures of the past. This paper provides an overview of the Marshall Space Flight Center's new approach to launch vehicle development, as well as examples of how that approach has been leveraged by NASA's Space Launch System (SLS) Program to achieve its key goals to safety, affordability, and sustainability.

New technology is changing the way we do business at NASA. The ability to use these new tools is made possible by a learning culture able to embrace innovation, flexibility, and prudent risk tolerance, while retaining the hard-won lessons learned of other successes and failures. Technologies such as 3-D manufacturing and structured light scanning are re-shaping the entire product life cycle, from design and analysis, through production, verification, logistics and operations. New fabrication techniques, verification techniques, integrated analysis, and models that follow the hardware from initial concept through operation are reducing the cost and time of building space hardware. Using these technologies to be more efficient, reliable and affordable requires we bring them to a level safe for NASA systems, maintain appropriate rigor in testing and acceptance, and transition new technology. Maximizing these technologies also requires cultural acceptance and understanding and balancing rules with creativity. Evolved systems engineering processes at NASA are increasingly more flexible than they have been in the past, enabling the implementation of new techniques and approaches. This paper provides an overview of NASA Marshall Space Flight Center's new approach to development, as well as examples of how that approach has been incorporated into NASA's Space Launch System (SLS) Program, which counts among its key tenants - safety, affordability, and sustainability. One of the 3D technologies that will be discussed in this paper is the design and testing of various rocket engine components.

A one-dimensional thermo-electro-mechanical mathematical model describing the effects taking place within a Ni-Cr20% wire used in a hot-wire cutting process for free forming and rapid prototyping of expanded polystyrene (EPS) is investigated and simulated. The model implements and solves three semi...... cutting of EPS in contact with a cutting tool made of an electrically heated metal wire attached to a robot device. The finite difference method is used to solve the coupled equations in the two environments (domains) in which the hot-wire operates, namely air and EPS. The model is calibrated against...

This paper presents the segmentation of the in 8 meter depth of water and for cutting through super alloyed moderator vessel and of the thermal shield of the MZFR stainless steel up to 130 mm wall thickness. Depending on the research reactor by means of under water plasma and contact arc metalcutting. The moderator vessel and the thermal shield are the most essential parts of the MZFR reactor vessel internals. These components have been segmented in 2005 by means of remotely controlled under water cutting utilizing a special manipulator system, a plasma torch and CAMC (Contact Arc MetalCutting) as cutting tools. The engineered equipment used is a highly advanced design developed in a two years R and D program. It was qualified to cut through steel walls of more than 100 mm thickness in 8 meters water depth. Both the moderator vessel and the thermal shield had to be cut into such size that the segments could afterwards be packed into shielded waste containers each with a volume of roughly 1 m 3 . Segmentation of the moderator vessel and of the thermal shield was performed within 15 months. (author)

Full Text Available In turning process, the cutting tool is essential for shaping materials. The cutting tools with various perforated surfaces help to increase the cutting tool life. Also, advances in CNC machining technologies have enhanced the productivity of machining process. One of the best or futuristic approaches in modern manufacturing engineering is the use of FEM Simulation for the metalcutting process. FEM simulation helps in understanding the metal deformation process and also helps in the reduction of experiments. The simulation helps the researchers to predict the major influencing cutting variable values without carrying out any experiment which is time-consuming and expensive. This research presents the simulation study of the performance of micro-hole patterned Polycrystalline Diamond cutting insert in machining Titanium alloy (Ti-6Al-4V. Micro-holes are drilled using Electrical Discharge Wire Drilling machine on the rake face of Polycrystalline Diamond (PCD cutting inserts. FEM analysis is carried out to evaluate the effect of perforations on the mechanical integrity of insert. The micro-hole patterned insert is modeled in PRO-E modeler and simulated using DEFORM-3D software. The effective stress, strain, and temperature distribution are analyzed and the results are compared with the normal insert.

Los Angeles Unified School District, CA. Div. of Career and Continuing Education.

This booklet is a course of instruction in metal working in a two-column, English-Spanish format. Following an introduction to metal working and a lesson on safety, the booklet contains 17 units organized in 2 parts. Part 1, bench metal work, covers metals, processes, and tools; cutting; filling; drilling; grinding; bending and shaping; threading;…

A cutting machine includes a gun barrel for receiving a projectile. A compression tube is disposed in flow communication with the barrel and includes a piston therein. A reservoir is disposed in flow communication with the tube and receives a first gas under pressure. A second gas fills the compression tube on a front face of the piston. And, the pressurized first gas is discharged into the tube on a back face of the piston to accelerate the piston through the tube for compressing the second gas, and in turn launching the projectile through the barrel to impact a workpiece.

Due to their high weight-specific mechanical stiffness and strength, parts made from carbon fiber reinforced polymers (CFRP) are increasingly used as structural components in the aircraft and automotive industry. However, the cutting of preforms, as with most automated manufacturing processes for CFRP components, has not yet been fully optimized. This paper discusses laser cutting, an alternative method to the mechanical cutting of preforms. Experiments with remote laser cutting and gas assisted laser cutting were carried out in order to identify achievable machining speeds. The advantages of the two different processes as well as their fitness for use in mass production are discussed.

Full Text Available The aim of this article is to demonstrate the efect of cutting materials and geometry of cutting tips on cutting forces in turning as well as the quality and precision of machined surface. The experiment focuses on measuring cutting forces when turning a sample of steel 11 523 at a constant feed rate and cut depth and at varying speeds of a spindle. Measurements were made using exchangeable cutting tips of diferent types. The results will be evaluated in terms of the impact of diferent characteristics of cutting tips and variable spindle speeds.

Micro-hole drilling and cutting in ambient air are presented by using a femtosecond fiber laser. At first, the micro-hole drilling was investigated in both transparent (glasses) and nontransparent (metals and tissues) materials. The shape and morphology of the holes were characterized and evaluated with optical and scanning electron microscopy. Debris-free micro-holes with good roundness and no thermal damage were demonstrated with the aspect ratio of 8∶1. Micro-hole drilling in hard and soft tissues with no crack or collateral thermal damage is also demonstrated. Then, trench micromachining and cutting were studied for different materials and the effect of the laser parameters on the trench properties was investigated. Straight and clean trench edges were obtained with no thermal damage.

Full Text Available A problem often coped on many domains such as wood manufacturing, glass, plastics and metallic platework industry, is the shaping or cutting off a big plate in many pieces. With this purpose there are algorithms of optimizing for positioning the parts following to be cut off from a row plate. From mathematical point of view, in positioning the parts on a raw plate the number of solutions increase four times evrey time a new part is added, and in case of finding the best solution for about few hundreds of pieces or parts would require years of processing on the most performant computers nowadays – for an analogy remember the famous story with the rice beads which the King had to pay to the master teaching him the chess: twice more for each square of the chessboard; for the total quantity assessment, King ascertained that the crops in his whole life wouldn’t have been enough.

The Laser Processing Facility of the Materials Fabrication Division of Lawrence Livermore National Laboratory has two pulsed Nd-YAG lasers mounted on machine tool bases. Over the years the authors have had requirements for cutting a wide variety of materials, frequently to very tight dimensional tolerances. They have found that the laser process is particularly well suited for two application areas; (1) for thin cross sections of most all materials, and (2) for refractory metals and ceramics such as tungsten, tantalum, and molybdenum, silicon wafers, alumina, and graphite foil. Some of these materials are difficult if not impossible to cut and drill in any other manner. Examples of each of these types of applications are sighted. Data are presented to illustrate the effects and interactions of laser parameter variables such as aperturing, choice of lenses, focus, pulse length, and energy level. Examples of applications are shown

Surface hardening has long been recognized as an important method of increasing the integrity and life of cutting tools. In this work we report preliminary investigations of hardening of conventional hard metal tools by ion implantation Three types of mixed carbide tool inserts were treated by bombardment with 40kV ions of Al, Ti, Zr or W in an ambient of Ar or N/sub 2/, with doses of up to 13*10/sup 17/ ions/cm/sup 2/. The samples were monitored by micro-hardness measurements. Complex behaviors as a function of the implantation dose/time have been observed, and are commented on in terms of the lattice disruption caused by the bombardment. Hardness increments of up to 22 % have been obtained using an ion implanter of industrial size, and cutting tests have shown an improvement, by a factor of three, in the life of these treated tools. (author)

A closed form solution to the problem of steady-state wedge cutting through a ductile metal plate is presented. The considered problem is an idealization of a ship bottom raking process, i.e. a continuous cutting damage of a ship bottom by a hard knife-like rock in a grounding event. A new...... extension of the presented plate model to include more structural members as for example the stiffeners attached to a ship bottom plating. The fracture process is discussed and the model is formulated partly on the basis of the material fracture toughness. The effect of friction and the reaction force...... perpendicular to the direction of motion is derived theoretically in a consistent manner. The perpendicular reaction force is of paramount importance for prediction the structural damage of a ship hull because it governs the vertical ship motion and rock penetration which is strongly coupled with the horizontal...

Full Text Available The ixora is ornamental plant widely used in landscaping. In order to maximize the propagation of cuts, we evaluated the concentrations of auxin (indolbutiric acid and the presence of leaves on the rooting in cuts of Ixora coccinea L. The experiment was conducted in randomized block design, in factorial design 3x4, with three types of cuts (without leaf, with two or four leaves, four concentrations of indolbutiric acid (0, 1000, 2000 and 4000 mg L-1, with four replications and 10 cuts in each experimental unit. After 53 days of implantation the experiment, evaluated the survival(%, rooting(%, sprouting(%, formation of callus(%, number, length and biomass of roots formed. The interaction of the type of cuts with concentrations of auxin was not significant for any of the variables analyzed. The survival of cuttings was not influenced by the treatments. Cuts with two or four leaves presented rooting and length of roots above the cuttings without leaves. The application of auxin does not substitute the presence of leaf in cuts of ixora in vegetative propagation. The vegetative propagation by cut of ixora can be made without application of auxin, and the leaves must be maintained in the cuttings.

Full Text Available In this paper elaborates the process of measuring cutting power which occurred during cutting six types of particle board. Chipboards with different physical and mechanical properties were cut in order to find some correlation with the cutting power ie to be able to determine the effect of moisture, density and bending strength of the plate to the cutting power. Measuring power cut was made in the workshop of the Faculty of Forestry, Belgrade, measuring the moisture and density in the laboratory for testing particle board, and the bending strength was performed in the laboratory for testing the properties of wood. During the cutting speed are changed auxiliary movements to determine the influence of the machining parameters on cutting power. Overall, it was concluded that with increasing moisture content of the work-piece cutting power decreases with increasing velocity displacement, density and bending strength of the board, required cutting power increases.

Timothy Firnstahl owns five successful restaurants in Seattle, but he recently came very close to owning none. In the early 1990s, he found himself, like so many restauranteurs, facing rising costs, inefficient management, and a recession. Confronting financial annihilation, Firnstahl had to act quickly: since he had no peripherals to trim, he cut off the head of his company. Remarkably, it worked. Firnstahl's problem was his new and innovative restaurant, Sharps Fresh Roasting. The heart of the Sharps concept was a unique long-roasting technique that made lean, inexpensive meats taste as juicy and delicious as fattier, expensive cuts. The process also lent itself to faster service and lower labor costs. But it wasn't working. Sharps wasn't breaking even, and his other restaurants couldn't make up the difference. He needed a solution fast. Firnstahl got his answer from Mikhail Gorbachev: slash the centralized command and liberate the company. In doing so, he would also transfer virtually all power and responsibility to his line managers. And after five months of intensive study and planning, he accomplished what he set out to do. He fired most of his corporate staff, empowered his restaurant managers with "100% Power and Responsibility," and, finally, undertook a massive promotion campaign. A year later, Sharps Fresh Roasting is the gold mine Firnstahl always believed it could be. He's done away with bureaucracy and turned business around in a down market. All this because his managers are managing themselves.

In this paper, we investigate the effect of cutting speed on flank wear, crater wear and finished surface roughness during hobbing using an uncoated tool, and TiN- and (Al, Ti)N- coated tools with a minimal quantity lubrication (MQL) system. The experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results helped clarify the following points. (1) With the uncoated tool and the TiN-coated tool, the flank wear increases upon increasing in the cutting speed from 47m/min to 86m/min. Conversely, flank wear decreases at the higher speed of 117m/min. It was impossible to cut at 159m/min owing to the failure of the cutting edge. With the (Al, Ti)N-coated tool, the flank wear showed nearly the same small value, irrespective of cutting speed. (2) The cutting speed also has a large effect on crater wear, particularly for the TiN-and (Al, Ti)N-coated tools. The cutting speed of 117m/min is suitable for decreasing crater wear. (3) The finished surface roughness is small for all the tools used in this test for cutting speeds less than 86m/min, after which it becomes large because of the adhesion of deposited metal at cutting speeds more than 117m/min. When using the TiN- and (Al, Ti)N-coated tools, there is a critical cutting groove length, at which the surface roughness decreases rapidly.

Technologies for processing surfaces and decomposition of installations under water will be presented and compared in their use for dismantling of nuclear facilities. For the removal of surfaces the dry ice- and the dry ice laser blasting process are examined. Experiences in the use of a 1kW Nd:YAG laser for under water cutting of metals are presented. An assisting tool to choose a suitable process for removing coatings and component's surfaces will be developed. The presented work is part of the progress made in a research project consisting of 11 partners: developers, operators and end-users. (orig.)

Remote Ablation Cutting (RAC) is a most promising process for cutting thin metal sheets in the automotive, medical and consumer industry. Characteristically for the RAC are high cutting velocities for metal foils as well as material processing of box structures without spatter contamination at the inner surface. Furthermore, the system technology for RAC can also be used for other processes, like welding and marking. Thereby, the flexibility of a production unit is increased, compared to a conventional cutting system. Despite several advantages, the RAC is not yet state of the art in industrial production. Reasons for that are lacking knowledge in the area of process itself and in possible application areas. In this paper a conceptual model of the ablation and the ejection mechanism is presented. It consists of the laser beam absorption within the processing zone, the melt ejection from the kerf and the resulting spatter formation above the part surface. Besides the model, the process boundaries and limitations are identified using empirical data. Addressing possible applications, the following samples of different industrial areas are introduced to show the potential of the process: Cutting of heat exchanger plates, cylinder head seals, and cathode/anode material for Li-Ion-Batteries. Furthermore, a concept and first results of the combined processing of remote cutting and welding with one laser and one scanner optics are presented.

by software Minitab (multiple linear regression and response surface methodology) in order to express the influence degree of the main cutting variables such as cutting speed, feed rate and depth of cut on cutting force components. These models would be helpful in selecting cutting variables for optimization of hard cutting ...

In micro milling the maximum uncut chip thickness is often smaller than the cutting edge radius. This paper introduces a new cutting force model for ball nose micro milling that is capable of taking into account the effect of the edge radius.......In micro milling the maximum uncut chip thickness is often smaller than the cutting edge radius. This paper introduces a new cutting force model for ball nose micro milling that is capable of taking into account the effect of the edge radius....

Pyrite and other minerals containing sulfur and trace metals occur in several rock formations throughout Middle and East Tennessee. Pyrite (FeS2) weathers in the presence of oxygen and water to form iron hydroxides and sulfuric acid. The weathering and interaction of the acid on the rocks and other minerals at road cuts can result in drainage with low pH (formation and remediation of acid-drainage from roads cuts has not been researched as thoroughly as acid-mine drainage. The U.S Geological Survey, in cooperation with the Tennessee Department of Transportation, is conducting an investigation to better understand the geologic, hydrologic, and biogeochemical factors that control acid formation at road cuts. Road cuts with the potential for acid-rock drainage were identifed and evaluated in Middle and East Tennessee. The pyrite-bearing formations evaluated were the Chattanooga Shale (Devonian black shale), the Fentress Formation (coal-bearing), and the Precambrian Anakeesta Formation and similar Precambrian rocks. Conceptual models of the formation and transport of acid-rock drainage (ARD) from road cuts were developed based on the results of a literature review, site reconnaissance, and the initial rock and water sampling. The formation of ARD requires a combination of hydrologic, geochemical, and microbial interactions which affect drainage from the site, acidity of the water, and trace metal concentrations. The basic modes of ARD formation from road cuts are; 1 - seeps and springs from pyrite-bearing formations and 2 - runoff over the face of a road cut in a pyrite-bearing formation. Depending on site conditions at road cuts, the basic modes of ARD formation can be altered and the additional modes of ARD formation are; 3 - runoff over and through piles of pyrite-bearing material, either from construction or breakdown material weathered from shale, and 4 - the deposition of secondary-sulfate minerals can store trace metals and, during rainfall, result in increased

Full Text Available Shear angle and sticking length are two crucial parameters in mechanics of metalcutting. These two parameters directly influence machinability factors such as cutting forces. Thus, shear angle and sticking length were investigated in vibratory turning process by using a pneumatic quick-stop device which was designed and fabricated, in this study. After preparation of ultrasonic assisted turning set-up, experimental tests have been carried out on two types of steel: AISI-1060 and AISI 304. Accordingly, the process of chip formation in each particular cutting test was quickly stopped when deformed chip was still in contact with workpiece. As a result, it was revealed that added linear vibration leads the turning operation to be improved by increase of shear angle and decrease of sticking length. Moreover, the effect of ultrasonic vibration on cutting force and chip micro-hardness is evaluated.

Diamond coatings on Co cemented tungsten carbide (WC-Co) hard metal tools are widely used for cutting non-ferrous metals. It is difficult to deposit diamond onto cutting tools, which generally have a complex geometry, using a single step growth process. This paper focuses on the deposition of polycrystalline diamond films onto dental tools, which possess 3D complex or cylindrical shape, employing a novel single step chemical vapour deposition (CVD) growth process. The diamond deposition is carried out in a hot filament chemical vapour deposition (HFCVD) reactor with a modified filament arrangement. The filament is mounted vertically with the drill held concentrically in between the filament coils, as opposed to the commonly used horizontal arrangement. This is a simple and inexpensive filament arrangement. In addition, the problems associated with adhesion of diamond films on WC-Co substrates are amplified in dental tools due to the very sharp edges and unpredictable cutting forces. The presence of Co, used as a binder in hard metals, generally causes poor adhesion. The amount of metallic Co on the surface can be reduced using a two step pre-treatment employing Murakami etching followed by an acid treatment. Diamond films are examined in terms of their growth rate, morphology, adhesion and cutting efficiency. We found that in the diamond coated dental tool the wear rate was reduced by a factor of three as compared to the uncoated tool

Abrasive waterjets are widely used in the fields of civil and mechanical engineering for cutting a great variety of hard materials including rocks, metals, and other materials. Cutting depth is an important index to estimate operating time and cost, but it is very difficult to predict because there are a number of influential variables (e.g., energy, geometry, material, and nozzle system parameters). In this study, the cutting depth is correlated to the maximum kinetic energy expressed in terms of energy (i.e., water pressure, water flow rate, abrasive feed rate, and traverse speed), geometry (i.e., standoff distance), material (i.e., α and β), and nozzle system parameters (i.e., nozzle size, shape, and jet diffusion level). The maximum kinetic energy cutting depth model is verified with experimental test data that are obtained using one type of hard granite specimen for various parameters. The results show a unique curve for a specific rock type in a power function between cutting depth and maximum kinetic energy. The cutting depth model developed here can be very useful for estimating the process time when cutting rock using an abrasive waterjet.

With the increased trend in automation of modern manufacturing industry, the human intervention in routine, repetitive and data specific activities of manufacturing is greatly reduced. In this paper, an attempt has been made to reduce the human intervention in selection of optimal cutting tool and process parameters for metalcutting applications, using Artificial Intelligence techniques. Generally, the selection of appropriate cutting tool and parameters in metalcutting is carried out by experienced technician/cutting tool expert based on his knowledge base or extensive search from huge cutting tool database. The present proposed approach replaces the existing practice of physical search for tools from the databooks/tool catalogues with intelligent knowledge-based selection system. This system employs artificial intelligence based techniques such as artificial neural networks, fuzzy logic and genetic algorithm for decision making and optimization. This intelligence based optimal tool selection strategy is developed using Mathworks Matlab Version 7.11.0 and implemented. The cutting tool database was obtained from the tool catalogues of different tool manufacturers. This paper discusses in detail, the methodology and strategies employed for selection of appropriate cutting tool and optimization of process parameters based on multi-objective optimization criteria considering material removal rate, tool life and tool cost.

... OF THE TREASURY LIQUORS âTIED-HOUSEâ Exceptions § 6.92 Newspaper cuts. Newspaper cuts, mats, or engraved blocks for use in retailers' advertisements may be given or sold by an industry member to a retailer selling the industry member's products. [T.D. ATF-364, 60 FR 20423, Apr. 26, 1995] ...

The harvesting of flowers and cuttings can be considered as a skilled task. It takes weeks of training for the pickers to harvest quality cutting at the required production rate of one per second. The skill of the pickers is the ability to execute a number of functions within a short time. The

Dec 9, 2016 ... The data of EEG from 60-second blocks prior to neck cut to 90-second blocks post neck cut were taken for statistical analysis based on the time to .... reported an initial increase in total EEG power in lambs of different ages undergoing rubber-ring castration. In these cases, the increase in total EEG power ...

In the past fifty years, the cut flower market has changed dramatically, from a local market with growers located on city outskirts, to a global one; flowers and cut foliage sourced from throughout the world are sold as bunches or combined into arrangements and bouquets in the major target markets. ...

To reduce damage to hardwood stems by grapevines, it is recommended that grapevines be cut near ground level several years before the harvest cutting. Cost of completing this practice on 117 acres supporting 22 vines per acre was found to be about $3.50 per acre.

This experimental investigation was conducted to determine the effects of cutting conditions on surface roughness and cutting forces in hard turning of X38CrMoV5-1. This steel was hardened at 50 HRC and machined with CBN tool. This is employed for the manufacture of helicopter rotor blades and forging dies. Combined ...

Literacy coordinator Martha Sandstead finds inspiration for her coaching work in a quote from civil rights organizer Lawrence Guyot: "Let's say you're riding past a picnic, and people are cuttin' watermelons. You don't immediately go and say, "stop the watermelon cutting" and let's talk. … You cut some watermelons, or you help…

Since the laser was invented in 1960, the industrial applications of this tool has grown and grown. And - since the beginning of the 1980'ies, the major industrial application of lasers in production has been laser cutting. In this paper a short review of the development of the laser cutting...

A system for forming a wellbore includes a drill tubular. A drill bit is coupled to the drill tubular. One or more cutting structures are coupled to the drill tubular above the drill bit. The cutting structures remove at least a portion of formation that extends into the wellbore formed by the drill bit.

It is shown that contributions of reggeon-pomeron cuts are suppressed in amplitudes with opposite natural to the reggeon. This suppression grows logarithmically with energy. The suppression in the πP cut is, however, found to be weak. Consequence on conspiracy is discussed

Abstract. This experimental investigation was conducted to determine the effects of cutting conditions on surface roughness and cutting forces in hard turning of. X38CrMoV5-1. This steel was hardened at 50 HRC and machined with CBN tool. This is employed for the manufacture of helicopter rotor blades and forging dies.

Abrasive Waterjet (AWJ) Machining is a recent non-traditional machining process. This technology is widely used in industry for cutting difficult-to-machine-materials, milling slots, polishing hard materials etc. AWJ machining has many advantages, e.g. it can cut net-shape parts, no heat is

The plastic deformation field in Friction Stir Welding (FSW) is compared to that in metalcutting. A shear surface around the FSW tool analogous to the metalcutting shear plane is identified and comprises the basis of the "rotating plug" flow field model and the "wiping" model of tool interaction with weld metal. Within the context of these models: The FSW shear rate is estimated to be comparable to metalcutting shear rates. The effect of tool geometry on the FSW shear surface is discussed and related to published torque measurements. Various FS W structural features are explained, including a difference in structure of bimetallic welds when alloys on the advancing and retreating sides of the weld seam are exchanged. The joining mechanism and critical parameters of the FSW process are made clear.

The results obtained during the INTEGRAL masks development program an implementing the HURA and MURA codes on tungsten plates of different thickness are presented. Hard scientific requirements on pixels size and location tolerances (tenths of microns over large areas -1 m 2 - and thickness from 0.5 mm to 60 mm) required the set up of a dedicated program for testing cutting technologies: laser, photochemical milling, spark machining and electro discharge wire cutting. After a very intensive test campaign the wire cutting process was selected as the optimum technology for code manufacturing . Accuracies achieved an the code cutting fulfill scientific requirements. In fact, they are 5 times better than required. Pixel size and centroids location accuracies of 0.01 mm over a 1 m 2 area have been obtained for the 10,000 pixels on IBIS, 100 pixels on SPI and 24000 pixels on JEM-X masks. Comparative results among different cutting technologies are also discussed. (author)

Full Text Available A review of state-of-the-art methods for cutting stock problem optimisation shows that the current methods lead to near-optimum results for the instantaneous optimisation of trim loss. Further optimisation of this activity would not bring a considerable improvement. Therefore, the paper treats cutting stock as a continuous business process and not as an isolated activity. An exact method for a general one-dimensional cutting stock problem is presented and tested. The method is mainly suitable for smaller orders. It is then applied to continuous cutting and used to develop a method for assessing cutting costs in consecutive time periods. The modified method finds a good solution over the whole time-span, rather than just local optima.

Full Text Available This paper presents of the influence on vibration of Co28Cr6Mo medical alloy machined on a CNC lathe based on cutting parameters (rotational speed, feed rate, depth of cut and tool tip radius. The influences of cutting parameters have been presented in graphical form for understanding. To achieve the minimum vibration, the optimum values obtained for rpm, feed rate, depth of cut and tool tip radius were respectively, 318 rpm, 0.25 mm/rev, 0.9 mm and 0.8 mm. Maximum vibration has been revealed the values obtained for rpm, feed rate, depth of cut and tool tip radius were respectively, 636 rpm, 0.1 mm/rev, 0,5 mm and 0.8 mm.

A novel asymmetric-cut variable-incident-angle monochromator was constructed and tested in 1997 at the Advanced Photon Source of Argonne National Laboratory. The monochromator was originally designed as a high heat load monochromator capable of handling 5-10 kW beams from a wiggler source. This was accomplished by spreading the x-ray beam out on the surface an asymmetric-cut crystal and by using liquid metal cooling of the first crystal. The monochromator turned out to be a highly versatile monochromator that could perform many different types of experiments. The monochromator consisted of two 18° asymmetrically cut Si crystals that could be rotated about 3 independent axes. The first stage (Φ) rotates the crystal around an axis perpendicular to the diffraction plane. This rotation changes the angle of the incident beam with the surface of the crystal without changing the Bragg angle. The second rotation (Ψ) is perpendicular to the first and is used to control the shape of the beam footprint on the crystal. The third rotation (Θ) controls the Bragg angle. Besides the high heat load application, the use of asymmetrically cut crystals allows one to increase or decrease the acceptance angle for crystal diffraction of a monochromatic x-ray beam and allows one to increase or decrease the wavelength bandwidth of the diffraction of a continuum source like a bending-magnet beam or a normal x-ray-tube source. When the monochromator is used in the doubly expanding mode, it is possible to expand the vertical size of the double-diffracted beam by a factor of 10-15. When this was combined with a bending magnet source, it was possible to generate an 8 keV area beam, 16 mm wide by 26 mm high with a uniform intensity and parallel to 1.2 arc sec that could be applied in imaging experiments.

As globalization brings people with incompatible attitudes into contact, cultural conflicts inevitably arise. Little is known about how to mitigate conflict and about how the conflicts that occur can shape the cultural evolution of the groups involved. Female genital cutting is a prominent example. Governments and international agencies have promoted the abandonment of cutting for decades, but the practice remains widespread with associated health risks for millions of girls and women. In their efforts to end cutting, international agents have often adopted the view that cutting is locally pervasive and entrenched. This implies the need to introduce values and expectations from outside the local culture. Members of the target society may view such interventions as unwelcome intrusions, and campaigns promoting abandonment have sometimes led to backlash as they struggle to reconcile cultural tolerance with the conviction that cutting violates universal human rights. Cutting, however, is not necessarily locally pervasive and entrenched. We designed experiments on cultural change that exploited the existence of conflicting attitudes within cutting societies. We produced four entertaining movies that served as experimental treatments in two experiments in Sudan, and we developed an implicit association test to unobtrusively measure attitudes about cutting. The movies depart from the view that cutting is locally pervasive by dramatizing members of an extended family as they confront each other with divergent views about whether the family should continue cutting. The movies significantly improved attitudes towards girls who remain uncut, with one in particular having a relatively persistent effect. These results show that using entertainment to dramatize locally discordant views can provide a basis for applied cultural evolution without accentuating intercultural divisions.

In Denmark 4,456 metal-on-metal (MoM) hip prostheses have been implanted. Evidence demonstrates that some patients develope adverse biological reactions causing failures of MoM hip arthroplasty. Some reactions might be systemic. Failure rates are associated with the type and the design of the Mo...

A Kevlar laminate has negative thermal expansion coefficient, which makes it difficult to machine at room temperaures using the conventional cutting tools. Contararily, laser machining of a Kevlar laminate provides advantages over the conventional methods because of the non-mechanical contact between the cutting tool and the workpiece. In the present study, laser circular cutting of Kevlar laminate is considered. The experiment is carried out to examine and evaluate the cutting sections. Temperature and stress fields formed in the cutting section are simulated in line with the experimental study. The influence of hole diameters on temperature and stress fields are investigated incorporating two different hole diameters. It is found that the Kevlar laminate cutting section is free from large size asperities such as large scale sideways burnings and attachemnt of charred residues. The maximum temperature along the cutting circumference remains higher for the large diameter hole than that of the small diameter hole. Temperature decay is sharp around the cutting section in the region where the cutting terminates. This, in turn, results in high temperature gradients and the thermal strain in the cutting region. von Mises stress remains high in the region where temperature gradients are high. von Mises stress follows similar to the trend of temperature decay around the cutting edges.

In traditional diamond cutting, the cutting force is usually large and it will affect tool life and machining quality. Elliptical vibration cutting (EVC) as one of the ultra-precision machining technologies has a lot of advantages, such as reduces cutting force, extend tool life and so on. It's difficult to predict the transient cutting force of EVC due to its unique elliptical motion trajectory. Study on chip formation will helpfully to predict cutting force. The geometric feature of chip has important effects on cutting force, however, few scholars have studied the chip formation. In order to investigate the time-varying cutting force of EVC, the geometric feature model of chip is established based on analysis of chip formation, and the effects of cutting parameters on the geometric feature of chip are analyzed. To predict transient force quickly and effectively, the geometric feature of chip is introduced into the cutting force model. The calculated results show that the error between the predicted cutting force in this paper and that in the literature is less than 2%, which proves its feasibility.

Full Text Available In traditional diamond cutting, the cutting force is usually large and it will affect tool life and machining quality. Elliptical vibration cutting (EVC as one of the ultra-precision machining technologies has a lot of advantages, such as reduces cutting force, extend tool life and so on. It’s difficult to predict the transient cutting force of EVC due to its unique elliptical motion trajectory. Study on chip formation will helpfully to predict cutting force. The geometric feature of chip has important effects on cutting force, however, few scholars have studied the chip formation. In order to investigate the time-varying cutting force of EVC, the geometric feature model of chip is established based on analysis of chip formation, and the effects of cutting parameters on the geometric feature of chip are analyzed. To predict transient force quickly and effectively, the geometric feature of chip is introduced into the cutting force model. The calculated results show that the error between the predicted cutting force in this paper and that in the literature is less than 2%, which proves its feasibility.

We investigated the influence of cutting water potential (Psicut) on rooting of juvenile hardwood (dormant) and softwood (succulent) stem cuttings of loblolly pine (Pinus taeda L.) propagated under varying substrate water potentials (Psisub) and volumes of mist application. Mist treatment and Psisub contributed to the Psicut of unrooted stem cuttings. When Psisub was held constant across mist treatments, mist treatment contributed strongly to Psicut. Substrate water potential affected rooting percentage when mist treatment was sub-optimal or excessive, otherwise mist treatment had a stronger effect than Psisub on rooting percentage. Cuttings rooted best when subjected to moderate cutting water potentials (-0.5 to -1.2 MPa) during the initial 4 or 5 weeks of the rooting period. Cuttings experiencing either severe water deficit or no water deficit rooted poorly. We conclude that the rooting environment should impose a moderate water stress on loblolly pine stem cuttings to achieve optimum rooting. Copyright 2004 Heron Publishing

Full Text Available The coated tools are regularly used in today's metalcutting industry. Because, it is well known that thin and hard coatings can reduce tool wear, improve tool life and productivity. Such coatings have significantly contributed to the improvements cutting economies and cutting tool performance through lower tool wear and reduced cutting forces. TiN coatings have especially high strength and low friction coefficients. During the cutting process, low friction coefficient reduce damage in cutting tool. In addition, maximum stress values between coating and substrate also decrease as the friction coefficient decreases. In the present study, stress analysis is carried out for HSS (High Speed Steel cutting tool coated with TiN. The effect of the friction coefficient between tool and chip on the stresses developed at the cutting tool surface and interface of coating and HSS is investigated. Damage zones during cutting process was also attempted to determine. Finite elements method is used for the solution of the problem and FRANC2D finite element program is selected for numerical solutions.

Over the past few years there has been an enormous increase in the use of tailored blanks, especially in the automotive industry. Often the sheets for tailored blanks are shear cut, but results have been reported that the allowable sheet gap distance should not exceed 0.1 mm in order to obtain...... sound welds. Laser cutting the sheets may therefore be an alternative to shear cutting, if the cut kerf squareness can be kept below 0.05 mm.In a number of systematic laboratory experiments the effects of the major process parameters in laser cutting have been investigated. Each cut was quantified...... by the squareness, the surface roughness and the burr height. Mild steel as well as high strength steel with and with out galvanisation with thickness' of 0.7(5) and 1.25 were used.In the tests the difference in cut quality between a 5" and a 7.5" focusing lens were tested and the effect of using pulsed mode laser...

Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

Secondary products (aerosol, gas and swarf) are released in the work area when cutting nuclear reactor components are underwater during component replacement. We studied the characteristics and behavior of the secondary products produced during cutting of highly radioactive metals using electric discharge machinery (EDM) underwater. The ratio of the weight of the aerosol produced to the melted weight of a workpiece that was cut using EDM, both with a Ag/W alloy electrode and a carbon electrode, was about 1x10 -3 . The aerosol had a high concentration of manganese with a high vapor pressure. The production ratio was expressed as the aerosol production rate (ppm)=-4.6x10 -2 Tb + 1.4x10 2 (Tb: boiling point (K)). The EDM cutting produced metal vapors which condensed into particles. Air-borne nickel carbonyl was produced during the EDM cutting of nickel and carbon monoxide with a carbon electrode, and a high efficiency particulate air filter and a charcoal filter were used effectively. In the case of a Ag/W electrode, the swarf contained oxide particles of around 20 μm and hydroxide particles with a diameter of around 10 μm. The water clean-up system was able to purify water with over 95% filtration efficiency using a 1 μm pore-pleated filter cartridge. (author)

Deferment cutting is a regeneration practice that resembles a seed-tree or shelterwood cutting. The difference is that residual trees are not cut when the reproduction becomes established. Instead, residual trees are left until new reproduction matures to sawtimber size, and another regeneration cut is the silvicultural objective. Hence, with deferment cutting specific...

This paper introduces a class of cuts, called reachability cuts, for the Vehicle Routing Problem with Time Windows (VRPTW). Reachability cuts are closely related to cuts derived from precedence constraints in the Asymmetric Traveling Salesman Problem with Time Windows and to k-path cuts...

Software may contain functionality that does not align with its architecture. Such cross-cutting concerns do not exist from the beginning but emerge over time. By analysing where developers add code to a program, our history-based mining identifies cross-cutting concerns in a two-step process. First, we mine CVS archives for sets of methods where a call to a specific single method was added. In a second step, simple cross-cutting concerns are combined to complex cross-...

This article presents a reconfigurable manufacturing execution system (RMES) filling the gap between enterprise resource planning and resource layer for pipe-cutting production with mass customisation and rapid adaptation to dynamic market, which consists of planning and scheduling layer and executive control layer. Starting from customer's task and process requirements, the cutting trajectories are planned under generalised mathematical model able to reconfigure in accordance with various intersecting types' joint, and all tasks are scheduled by nesting algorithm to maximise the utilisation rate of rough material. This RMES for pipe cutting has been effectively implemented in more than 100 companies.

We study cut elimination for a multifocused variant of full linear logic in the sequent calculus. The multifocused normal form of proofs yields problems that do not appear in a standard focused system, related to the constraints in grouping rule instances in focusing phases. We show that cut...... elimination can be performed in a sensible way even though the proof requires some specific lemmas to deal with multifocusing phases, and discuss the difficulties arising with cut elimination when considering normal forms of proofs in linear logic....

Metalcutting techniques that can be used to segment the reactor pressure vessel of the Experimental Boiling Water Reactor (EBWR) at Argonne National Laboratory (ANL) have been evaluated by Nuclear Energy Services. Twelve cutting technologies are described in terms of their ability to perform the required task, their performance characteristics, environmental and radiological impacts, and cost and schedule considerations. Specific recommendations regarding which technology should ultimately be used by ANL are included. The selection of a cutting method was the responsibility of the decommissioning staff at ANL, who included a relative weighting of the parameters described in this document in their evaluation process. 73 refs., 26 figs., 69 tabs

Metalcutting techniques that can be used to segment the reactor pressure vessel of the Experimental Boiling Water Reactor (EBWR) at Argonne National Laboratory (ANL) have been evaluated by Nuclear Energy Services. Twelve cutting technologies are described in terms of their ability to perform the required task, their performance characteristics, environmental and radiological impacts, and cost and schedule considerations. Specific recommendations regarding which technology should ultimately be used by ANL are included. The selection of a cutting method was the responsibility of the decommissioning staff at ANL, who included a relative weighting of the parameters described in this document in their evaluation process. 73 refs., 26 figs., 69 tabs.

, and less still on the use of non-metallic reinforcements such as FRP (Fibre Reinforced Polymers) to ensure sufficient load bearing capacity. This paper proposes a new procedure based on limit analysis theory for evaluating the ultimate load of walls with cut-out openings that have been strengthened......Building refurbishment works frequently require the cutting of new openings in concrete walls. Cutting new openings weakens the overall response of such elements, so they usually require strengthening. However, current design codes offer little guidance on strengthening walls with openings...

This article investigates politicians’ preferences for cutting and spending. The research questions are where do politicians prefer to cut, where do they prefer to spend and how is this influenced by political ideology? These questions are investigated in a large-scale survey experiment fielded...... to Danish local councillors, who are randomly assigned to a decision-making situation, where the block grant provided to their municipality is either increased or reduced. The results show that the politicians’ preferences for cutting and spending are asymmetric, in the sense that the policy areas, which...... are assigned the least cuts when the grant is reduced, are rarely the ones which are assigned extra money when the grant is increased. Areas with well-organised interests and a target group which is perceived as deserving are granted more money, whereas policy areas where the target group is perceived as less...

Plasma cutting is a metal fabrication process that employs an electrically conductive plasma arc to cutmetals. The metal fume emitted from stainless steel plasma cutting may consist of hexavalent chromium (Cr6+), which is a carcinogen, and other toxicants. Overexposure to plasma cutting fume may cause pulmonary toxicity and other health effects. This study was to evaluate the effects of operation parameters (arc current and arc time) on the fume formation rates, Cr6+ and other oxides concentrations, particle size distributions (PSD), and particle morphology. A fume chamber and high-volume pump were used to collect fume produced from cutting ER308L stainless steel plates with arc currents varying between 20 and 50 A. The amount of fume collected on glass fiber filters was gravimetrically determined and normalized to arc time. Cr6+ and other oxides in the fume were analyzed using ion chromatography. PSD of the fume was examined using a scanning mobility particle sizer and an aerodynamic particle sizer for fine and coarse fractions, respectively. The particle morphology was imaged through a transmission electron microscope (TEM). Total fume generation rate increased with arc current and ranged from 16.5 mg min-1 at 20 A to 119.0 mg min-1 at 50 A. Cr6+ emissions (219.8-480.0 µg min-1) from the plasma cutting were higher than welding fume in a previous study. Nitrogen oxides level can be an indicator of oxidation level and Cr6+ formation (R = 0.93). Both PSD measurement and TEM images confirmed a multimodal size distribution. A high concentration of a fine fraction of particles with geometric mean sizes from 96 to 235 nm was observed. Higher arc current yielded more particles, while lower arc current was not able to penetrate the metal plates. Hence, the worker should optimize the arc current to balance cut performance and fume emission. The findings indicated that arc current was the dominant factor in fume emission from plasma cutting. Appropriate ventilation and

The Robotics Development Group at the Savannah River Technology Center has developed and implemented a scheme to perform automatic cutting of metallic contaminated waste. The scheme employs a plasma arc cutter in conjunction with a laser ranging sensor attached to a robotic manipulator called the Telerobot. A software algorithm using proportional control is then used to perturb the robot's trajectory in such a way as to regulate the plasma arc standoff and the robot's speed in order to achieve automatic plasma arc cuts. The scheme has been successfully tested on simulated waste materials and the results have been very favorable. This report details the development and testing of the scheme

In this study, a cutting tool is developed from duplex stainless steel (DSS) using the superplastic boronizing technique. The feasibility of the development process is studied, and the cutting performances of the cutting tool are evaluated and compared with commercially available carbide and high-speed steel (HSS) tools. The superplastically boronized (SPB) cutting tool yielded a dense boronized layer of 50.5 µm with a surface hardness of 3956 HV. A coefficient of friction value of 0.62 is obtained, which is lower than 1.02 and 0.8 of the carbide and HSS tools. When tested on an aluminum 6061 surface under dry condition, the SPB cutting tool is also able to produce turning finishing below 0.4 µm, beyond the travel distance of 3000 m, which is comparable to the carbide tool, but produces much better results than HSS tool. Through superplastic boronizing of DSS, it is possible to produce a high-quality metal-based cutting tool that is comparable to the conventional carbide tool.

Full Text Available Generally the study, evaluation and general understanding of end milling cutters are complicated by the complexity of the cutting process and of the cutting tool. The main performance factor of the end milling cutters is given by the durability of the tool. In practice the sound analysis of the tool engaged in the cutting process is used as a simple predictability mean to forecast the future durability of the tool. An alternative or complementary tool to predict future durability is the investigation of the chip behaviour. Chip behaviour investigations can also give clues concerning the possible improvement of the cutting tools. The current article presents a detailed chip behaviour investigation for 5-fluted end milling cutters with different performances and various geometries when approaching different types of metalcutting operations in 42CrMo4 alloy steel. Current study can be applied in future researches regarding the evaluation and the development of end milling cutters. Furthermore the current approach can be used on other types of cutting tools.

Consider a layer consisting of a m3m dielectric crystal, with faces cut parallel to a symmetry plane. Then bond it onto a semi-infinite mm2 piezoelectric substrate. For a X- or Y-cut of the substrate, a Love wave can propagate in the resulting structure and the corresponding dispersion equation is derived analytically. It turns out that when the upper (free) face of the layer is metalized, a fully explicit treatment can also be conducted in the case of a Y-cut rotated about Z. In the case of a germanium layer over a potassium niobate substrate, the wave exists at any wavelength for X-and Y-cuts but this ceases to be the case for rotated cuts, with the appearance of forbidden ranges. By playing on the cut angle, the Love wave can be made to travel faster than, or slower than, or at the same speed as, the shear bulk wave of the layer. A by-product of the analysis is the derivation of the explicit secular equation for the Bleustein-Gulyaev wave in the substrate alone, which corresponds to an asymptotic behavior of the Love wave. The results are valid for other choices for the layer and for the substrate, provided they have the same, or more, symmetries.

Some commercial nuclear power plants have been permanently shut down to date and decommissioned using dismantling methods. Other operating plants have decided to undergo an upgrade process that includes replacement of reactor internals. In both cases, there is a need to perform a segmentation of the reactor vessel internals with proven methods for long term waste disposal. Westinghouse has developed several concepts to dismantle reactor internals based on safe and reliable techniques, including plasma arc cutting (PAC), abrasive waterjet cutting (AWJC), metal disintegration machining (MDM), or mechanical cutting. Mechanical cutting has been used by Westinghouse since 1999 for both Pressurized Water Reactors (PWR's) and Boiling Water Reactors (BWR's) and its process has been continuously improved over the years. The complexity of the work requires well designed and reliable tools. Different band saws, disc saws, tube cutters and shearing tools have been developed to cut the reactor internals. All of those equipments are hydraulically driven which is very suitable for submerged applications. Westinghouse experience in mechanical cutting has demonstrated that it is an excellent technique for segmentation of internals. In summary, the purpose of this paper will be to provide an overview of the Westinghouse mechanical segmentation process, based on actual experience from the work that has been completed to date. (author)

We have developed the first tuneable channel cut crystal for ultra small angle neutron scattering and neutron optical experiments. The Darwin range of a perfect crystal can be reduced down to a fraction of its natural width. This “Darwin reduction” was realised without any change of the beam geometry which yields an intensity gain relative to conventional asymmetric Bragg diffraction. With such tuneable channel cut crystal peaks nearly δ-peaks can experimentally be realised.

A new type of rf cavity using a high permeability magnetic alloy (MA) will be used for the J-PARC high intense proton synchrotrons. The cut core configuration has been adopted to get the optimum Q-value of MA core. We observed the cut surface of MA cores obtained by water jet and grind stone cut. The results show that the roughness of the cut surfaces by grind stone cut is much smaller than by water jet cut so that the cut core by grind stone cut has a possibility to reduce the temperature rise around the cut surface. We developed a grind stone cutting machine for large core and cut large cores by using this machine. High power test of those cores have been performed and we did not observe the temperature rise around the cut surface. (author)

In Denmark 4,456 metal-on-metal (MoM) hip prostheses have been implanted. Evidence demonstrates that some patients develope adverse biological reactions causing failures of MoM hip arthroplasty. Some reactions might be systemic. Failure rates are associated with the type and the design of the Mo......M hip implant. A Danish surveillance programme has been initiated addressing these problems....

An experimental study of abrasive waterjet (AWJ) cutting of beef, pork and lamb meat with and without bone is presented. Salt particles were used as the abrasives. It has been found that an AWJ could significantly increase the depth of cut with much improved cut quality in cutting pure meat as compared to plain (or pure) waterjet cutting, while a plain waterjet was incapable of cutting bone satisfactorily. The study shows that AWJ cutting produced a very narrow kerf of less than 1mm and hence resulted in mush less meat loss than the traditional cutting processes, and meat can be cut at room temperature to eliminate the freezing or chilling costs. It is shown that a traverses speed of 20mm/s can be used to cut through 44mm thick beef rib bones with good cut quality. When slicing pure meat of 150mm thickness, the traverse speed of 66.67mm/s can yield very good cut quality. It is suggested that AWJ cutting is a viable technology for meat cutting. Plausible trends for the depth of cut, cutting rate and cut quality with respect to the process variables are discussed. Recommendations are finally made for the selection of the most appropriate process parameters for cutting meat of a given thickness.

Plasma arc cutting is a widely used industrial process in which an electric arc in the form of a high velocity plasma jet is used to melt and blow away metal. The arc attaches inside the resulting cut slot, or kerf, where it both provides a large heat flux and determines the flow dynamics of the plasma. Knowledge of the position of the arc attachment is essential for understanding the phenomena present at the work piece. This work presents a new method of measuring the location of the arc attachment in which the arc voltage is measured during the cutting of a range of work piece thicknesses. The attachment location is then interpreted from the voltages. To support the validity of this method, the kerf shape, dross particle size and dross adhesion to the work piece are also observed. While these do not conclusively give an attachment location, they show patterns which are consistent with the attachment location found from the voltage measurements. The method is demonstrated on the cutting of mild steel, where the arc attachment is found to be stationary in the upper portion of the cut slot and in reasonable agreement with existing published findings. For a process optimized for the cutting of 12.7 mm mild steel, the attachment is found at a depth of 1.5–3.4 mm. For a slower process optimized for the cutting of 25.4 mm mild steel, the attachment is found at a depth of 3.4–4.8 mm, which enhances heat transfer further down in the kerf, allowing cutting of the thicker work piece. The use of arc voltage to locate the position of the arc attachment is unique when compared with existing methods because it is entirely independent of the heat distribution and visualization techniques. (paper)

Laser cutting of various materials including Ti-6Al-4V alloy, steel 304, Inconel 625, and alumina is carried out to assess the kerf width size variation along the cut section. The life cycle assessment is carried out to determine the environmental impact of the laser cutting in terms of the material waste during the cutting process. The kerf width size is formulated and predicted using the lump parameter analysis and it is measured from the experiments. The influence of laser output power and laser cutting speed on the kerf width size variation is analyzed using the analytical tools including scanning electron and optical microscopes. In the experiments, high pressure nitrogen assisting gas is used to prevent oxidation reactions in the cutting section. It is found that the kerf width size predicted from the lump parameter analysis agrees well with the experimental data. The kerf width size variation increases with increasing laser output power. However, this behavior reverses with increasing laser cutting speed. The life cycle assessment reveals that material selection for laser cutting is critical for the environmental protection point of view. Inconel 625 contributes the most to the environmental damages; however, recycling of the waste of the laser cutting reduces this contribution.

Full Text Available Deposit welding is the application of a layer of metal on the surface of a product using fusion welding. In this paper, we consider the method of improving the technology of gas laser cutting, which makes it possible to achieve a high productivity of manufacturing a bimetallic tool. The present paper is concerned with the advantages of gas laser cutting which allows to consider this particular process of separating materials as highly-productive, low-waste, and advanced method of removing allowances of weld-deposit high-speed steel on the working surfaces of bimetallic tool. Urgency of the use of deposit welding and gas laser cutting to improve the efficiency of production of bimetallic tool is shown. The comparative analysis of gas-laser cutting and other cutting methods is given according to the geometrical parameters of cutting and surface quality. Analysis of the results of experimental studies has confirmed the high technological attractiveness and economic efficiency of manufacturing composite structures of punches and matrices when applying deposit welding of cutting parts with high-speed steels. The cost of dimensional processing of the welded cutting part is reduced by 4 to 6 times, while the manufacturing time is reduced by 6 to 12 times.

Full Text Available Vegetable oils (palm oil, groundnut oil, shear butter oil and cotton seed oil have been used as lubricants in the turning operation of aluminum under varying spindle speeds, feed rates and depths of cut and the results compared with kerosene (due to the gummy nature of aluminium metal. The parameters investigated are the chip thickness ratio, surface finish and surface temperature. Their performances when compared with the conventional soluble oil have shown that they can perform the same functions as imported ones in the machining of aluminum. They reduced chip thickness ratio, improved surface finish and exhibited good cooling behaviour at the work piece-tool interface. This performance is due to their high viscosities and the presence of surface active agents such as stearic acid and halogens, such as chlorine which help to reduce surface energy of a liquid and increase its wetting ability or oiliness.

Full Text Available Pyrotechnic release devices such as explosive bolts are prevalent for many applications due to their merits: high reliability, high power-to-weight ratio, reasonable cost, and more. However, pyroshock generated by an explosive event can cause failures in electric components. Although pyroshock propagations are relatively well understood through many numerical and experimental studies, the prediction of pyroshock generation is still a very difficult problem. This study proposes a numerical method for predicting the pyroshock of a ridge-cut explosive bolt using a commercial hydrocode (ANSYS AUTODYN. A numerical model is established by integrating fluid-structure interaction and complex material models for high explosives and metals, including high explosive detonation, shock wave transmission and propagation, and stress wave propagation. To verify the proposed numerical scheme, pyroshock measurement experiments of the ridge-cut explosive bolts with two types of surrounding structures are performed using laser Doppler vibrometers (LDVs. The numerical analysis results provide accurate prediction in both the time (acceleration and frequency domains (maximax shock response spectra. In maximax shock response spectra, the peaks due to vibration modes of the structures are observed in both the experimental and numerical results. The numerical analysis also helps to identify the pyroshock generation source and the propagation routes.

Full Text Available Grinding operations are very significant among the manufacturing processes of the metal-mechanic industry. In conventional grinding, cutting fluids are of great concern for improving productivity, but also for being hazardous to the environment. In order to contribute to the knowledge of the actual toxic effects of these products in aquatic environments, the present work assesses the toxicity potential through acute toxicity tests of three different kinds of cutting fluids, with three different usage times. The tests were carried out using the fish Poecilia reticulate and the microcrustacean Daphnia magna as test organisms. These tests made it possible to determine the Median Lethal Concentration (LC50 for the fish and the Median Effective Concentration (EC50 for the microcrustacean. The results indicate that, after storage, the toxicity potential of cutting fluids decreases. However, in the three situations investigated, the product presented a high toxicity potential, which reinforces the need of special care in its handling, usage and disposal.

Full Text Available Suicide notes are usually written with pen or marker on a paper, notebook, wall or mirror. However, suicide notes written on one’s own body is very rare, and suicide note engraved with some metallic object on the body has not been reported yet. In the present suicidal death, the victim while carving some letters on the left arm with a razor had an incidental cut on right thumb. This incidental cut on the palm may be referred as “cutaneous cut sign” which gives a clue that the carving on the body with a sharp object was written by the victim himself. It also provides an additional importance of examination of palm for the presence of supportive evidences.

The objective of this work is to cut large diameter contaminated pipes from the CO 2 cooling system of the gas-cooled reactors by means of explosive charges and to use the resulting shock wave to remove part of the contamination fixed inside the pipe. Two types of tests have been conducted using different explosives in different forms (the decontamination and the cutting tests) and are described. After testing the cutting modules and decontamination fuses, the effects of the detonations on the environment have been measured and were greater than expected. A metal containment device was therefore designed to absorb part of the energy dissipated by the shock wave and retain the debris from the explosions. A description of the tests conducted for this purpose is given. (O.L.). 7 figs., 3 tabs

Powerful lasers represent a promising alternative solution to traditional cutting processes used in dismantling nuclear equipments. The use of optical fibers has an unquestionable advantage when dealing with airtight workshops. A study funded by COGEMA Marcoule was undertaken by IRSN/SERAC in collaboration with GIP/GERAILP in order to characterise the aerosols emitted by the cutting of evaporators elements with a 4 kW continuous wave Nd:YAG laser. For this study, laser cutting has been carried out in a tight room of 35 m 3 connected to a particle sampling pipe. Iso-kinetic samplers allowed the measurement of the aerosol concentration. A diffusional and inertial spectrometer (SDI 2001) - an Andersen impinger coupled to a diffusion battery - provided the size distribution. An electrostatic filter used upstream a HEPA filter, itself placed before the extractor fan, collected the majority of the emitted aerosol. Its efficiency was measured and controlled throughout the experiments. The results show the influence of the cutting conditions on the characteristics of the aerosol, and allow a comparison with other cutting tools. (authors)

The majority of college financial aid offices have seen cuts to their operating budgets this year compared to the 2007-08 academic year when the recession began, according to the National Association of Student Financial Aid Administrator's latest QuickScan Survey. Sixty-two percent of financial aid offices reported operating budget cuts this year…

To investigate the changes in total antioxidant activity of fresh-cut tomato during storage, tomato fruits harvested at three different stages of maturity were cut into 7-mm thick slices and stored at 5 °C. Intact fruits were stored in the same conditions as a control. The antioxidant activity was

Full Text Available Correct and stable machining process requires an appropriate cutting tool. In most cases the tool can be selected by using special tool catalogs often available in online version. But in some cases there is a need to design unusual tools, for special treatment, which are not available in tool manufacturers’ catalogs. Proper tool design requires strength and geometric calculations. Moreover, in many cases specific technical documentation is required. By using Computer Aided Design of cutting tools this task can be carried out quickly and with high accuracy. Cutting tool visualization in CAD programs gives a clear overview of the design process. Besides, these programs provide the ability to simulate real machining process. Nowadays, 3D modeling in CAD programs is a fundamental tool for engineers. Therefore, it is important to use them in the education process.

Instrumentation and techniques are described to image small objects, such as but not limited to individual human chromosomes, with nanometer resolution. This instrument and method are also used to cut-off identified parts of objects, to move around and manipulate the cut-off parts on the substrate on which they are being imaged to predetermined locations on the substrate, and to remove the cut-off parts from the substrate. This is accomplished using an atomic force microscope (AFM) and by modification of the conventional cantilever stylus assembly of an AFM. The plural cantilevers are used with either sharp-tips or knife-edges. In addition, the invention can be utilized for measuring the hardness of materials. 10 figs.

Manufacturing is the basic industrial activity generating real value. Cutting and abrasive technologies are the backbone of precision production in machine, automotive and aircraft building as well as of production of consumer goods. We present the knowledge of modern manufacturing in these technologies on the basis of scientific research. The theory of cutting and abrasive processes and the knowledge about their application in industrial practice are a prerequisite for the studies of manufacturing science and an important part of the curriculum of the master study in German mechanical engineering. The basis of this book is our lecture “Basics of cutting and abrasive processes” (4 semester hours/3 credit hours) at the Leibniz University Hannover, which we offer to the diploma and master students specializing in manufacturing science.

Cut welding is a newly developed cold pressure welding process. In the present work, an experimental investigation was carried out analyzing the mechanisms involved in cut welding of a block to a strip. Experiments were carried out in technically pure aluminium. The investigation has involved...... tensile testing and metallographic investigations of the welds. The results show that this variant of cut welding is a very reproducible process giving a weld strength equal to 30-40% the strength of the parent material. The experiments have shown that the reason for this relatively low strength...... is an uneven pressure distribution along the weld due to a wave formed during sliding. Attempts to alter the material flow during sliding are presented....

Self-mutilation or cutting is not uncommon and may be detected in the workplace. It stems from an underlying psychological illness, specifically borderline personality disorder (BPD). Individuals diagnosed with BPD are usually attempting to handle negative childhood experiences and feelings of abandonment. They often overreact to social stress and engage in cutting to alleviate uncomfortable feelings. A small percentage go on to attempt suicide. Dialectical behavior therapy (DBT) is the preferred treatment modality for individuals with BPD. Occupational health nurses are in a pivotal position to identify workers who cut and to refer them to appropriate treatment options. In addition, occupational health nurses can learn to reinforce the social skills learned in DBT.

The biological shield concrete and the radiation shield concrete which construct a part of the atomic reactor must be demolished with the decommissioning of the atomic reactor plants. In a case, the demolition using a laser is expected as one of excellent method for the decommissioning of these radioactive concretes. The fundamental cuttings of a mortar, the concretes with andesite, lime stone and gray wacke as ballast and a concrete reinforced with mild steel rods were therefore carried out using a 5 kW output CO 2 laser. As the results of experiment, it was cleared that cutting results varied with ballasts, 100 mm thick reinforced concrete could be cut, safety was high because few dross and few fume were produced. (author)

Full Text Available The most important input quantities of waterjet cutting are the jet pressure, feed speed, stand-off distance, abrasive graining, mass flow, etc. Other quantities contributing to machining efficiency are the type of utilized abrasive or the tilt of the jet. Each of these quantities can be assigned different set points. The roughness of the machined surfaces and the thickness of the cut part are output quantities of the system, their values depending on the input parameters and the influence of various disturbing factors (noises. The paper discusses surface roughness obtained consequently to abrasive jet cutting. Optimisation of the machining system was achieved by intervening on five selected input quantities (factors, with two set points considered for each. Upon applying Taguchi methods, eventually the combination of factor set points was determined that ensures robust behaviour of the system.

Highlights: • Different TIG and Laser welding techniques are tested. • Twin spot laser welding techniques is the best. • Limited heat input gives a stable weld pool in all positions. • Penetrations is achieved. • Lip seal welding and cutting with a robotic arm is successfully performed on a representative mock-up. - Abstract: The welded lip seals form part of the torus primary vacuum boundary in between the port plugs and the vacuum vessel, and are classified as Protection Important Component. In order to refurbish the port plugs or the in-vessel components, port plugs have to be removed from the machine. The lip seal design must enable up to ten opening of the vacuum vessel during the life time operation of the ITER machine. Therefore proven, remote reliable cutting and re-welding are essential, as these operations need to be performed in the port cells in a nuclear environment, where human presence will be restricted. Moreover, the combination of size of the components to be welded (∼10 m long vacuum compatible thin welds) and the congested environment close to the core of the machine constraint the type and size of tools to be used. This paper describes the lip seal cutting and welding development programme performed at the VTT Technical Research Centre, Finland. Potential cutting and welding techniques are analyzed and compared. The development of the cutting, TIG and laser welding techniques on samples are presented. Effects of lip seal misalignments and optimization of the 2 welding processes are discussed. Finally, the manufacturing and test of the two 1.2 m × 1 m representative mock-ups are presented. The set-up and use of a robotic arm for the mock-up cutting and welding operations are also described.

Full Text Available The purpose of this paper is to provide a governance structure for IT-related projects in order to assure a safeguarded and timely transition to a productive environment. This transitioning, which rarely exceeds a weekend, is colloquially called ‘cut-over’, ‘rollout’ or ‘deployment’. The governance structure is defined in accordance with a set of project-specific deliverables for a cascade-type procedural project-management model, which is integrated within an Information Technology Infrastructure Library (ITIL-orientated service organization. This integration is illustrated by the use of a semi-agile release model. Due to the release model selected, which is particularly characterized by its bundling of projects for a release-specific rollout (as it is referred to in the project documentation, a new definition and interpretation of deployment from a generic ITIL perspective is required. The facilitated release model requires a distinction between a project-specific cut-over and a release-specific rollout. This separation gives rise to two types of go-live scenarios: one for each participating project and one for each release. Additionally, an interplay between cut-over planning for a project and rollout planning for a release becomes apparent. Projects should already incorporate cut-over related deliverables in the initial planning phase. Even though consulting methodologies such as ASAP (Accelerated SAP, recommend scattered, project-specific deliverables useful for cut-over planning, this publication offers an integrated approach on how to prepare systematically for a project-specific cut-over with all required deliverables. The framework provided maps out ITIL’s release and deployment process by means of IT projects; furthermore it allows IT projects to interface easily with the ITIL change-management process.

In this study, the effect of in vitro cutting methods and medium composition on efficient shoot multiplication of Paphiopedilum Hsinying Rubyweb was investigated. Among three different in vitro stem cutting methods used, vertical cutting was able to produce more new shoots than horizontal and cross cutting when cultured on ...

was developed and implemented on a CNC lathe. An investigation was carried out extrusion-cutting copper discs using high-speed-steel cutting tools at 100 m/min cutting speed. Flow stress values for copper under machining-relevant conditions were obtained from measurement of the extrusion-cutting force...

The latest development in and different aspects of modified atmosphere packaging for fresh-cut fruits and vegetables are reviewed in the book. This book provides all readers, including fresh-cut academic researchers, fresh-cut R&D personnel, and fresh-cut processing engineers, with unique, essential...

The paper describes the influence of local variations of contact length, cutting speed and material constraint, showing the effect of lubrication, on the side curl of the chip. The following examples are illustrated by experiments: cutting of a tube vs. cutting of a bar; cutting using a tool...

... 49 Transportation 4 2010-10-01 2010-10-01 false Torch cut rail. 213.352 Section 213.352... Torch cut rail. (a) Except as a temporary repair in emergency situations no rail having a torch cut end shall be used. When a rail end with a torch cut is used in emergency situations, train speed over that...

... 7 Agriculture 3 2010-01-01 2010-01-01 false Cutting and packaging rooms. 58.413 Section 58.413....413 Cutting and packaging rooms. When small packages of cheese are cut and wrapped, separate rooms... outward to minimize the entrance of unfiltered air into the cutting and packaging room. The waste...

In this paper, recent results in high power laser cutting, obtained in reseach and development projects are presented. Two types of mirror based focussing systems for laser cutting have been developed and applied in laser cutting studies on CO2-lasers up to 12 kW. In shipyard environment cutting...

Liposuction is often used for the treatment of gynecomastia. Blunt liposuction cannulas can remove the fat but are not very effective in fibrous breast tissue, which requires open excision. Ultrasound-assisted lipoplasty has been advocated for gynecomastia because it effectively removes the fat from fibrous areas. An alternative treatment is a sharp cutting liposuction cannula that easily penetrates and removes the fibrous breast tissue along with the fatty component. The early experience of 22 surgeons who used this cannula in 88 cases of gynecomastia is reported. For 19 of the 22 surgeons, liposuction with sharp cutting cannulas alone gave a satisfactory result in 81% of their patients.

In this paper we present a method for appproximating cut loci for a given point p on Riemannian 2D manifolds, closely related to the notion of Voronoi diagrams. Our method finds the cut locus by advecting a front of points equally distant from p along the geodesics originating at p and finding...... the lines of self-intersections of the front in the parametric space. This becomes possible by using the deformable simplicial complexes (DSC, [1]) method for deformable interface tracking. DSC provide a simple collision detection mechanism, allows for interface topology control, and does not require...

by authors of the paper, which facilitates high-speed production of doubly-curved foam moulds. Complementary to design rationalisation, in which arbitrary surfaces are translated to hot-blade-cuttable geometries, the presented method enables architects and designers to design directly with the non......-trivial constraints of blade-cutting in a bottom-up fashion, enabling an exploration of the unique architectural potential of this fabrication approach. The method is implemented as prototype design tools in MatLAB, C++, GhPython, and Python and demonstrated through cutting of expanded polystyrene foam design...

We discuss symplectic cutting for Hamiltonian actions of non-Abelian compact groups. By using a degeneration based on the Vinberg monoid we give, in good cases, a global quotient description of a surgery construction introduced by Woodward and Meinrenken, and show it can be interpreted in algebro......-geometric terms. A key ingredient is the `universal cut' of the cotangent bundle of the group itself, which is identified with a moduli space of framed bundles on chains of projective lines recently introduced by the authors....

This paper presents the segmentation of the moderator vessel and of the thermal shield of the MZFR research reactor by means of under water plasma and contact arc metalcutting. The moderator vessel and the thermal shield are the most essential parts of the reactor vessel internals. These components have been segmented in 2005 by means of remotely controlled under water cutting utilizing a special manipulator system, a plasma torch and CAMC (Contact Arc MetalCutting) as cutting tools. The engineered equipment used is a highly advanced design developed in a two years R and D program. It was qualified to cut through steel walls of more than 100 mm thickness in 8 meters water depth. Both the moderator vessel and the thermal shield had to be cut into such size that the segments could afterwards be packed into shielded waste containers each with a volume of roughly 1 m 3 . Segmentation of the moderator vessel and of the thermal shield was performed within 15 months. (authors)

The metallic ladder built in stainless steel was used originally to check the welding of the reactor pressure vessel. It was located between the thermal insulation and reactor pressure vessel. Because of a failure in the mechanism, which let the ladder runs around the vessel, it had to be removed. A special tool remotely operated was designed to make different cuts in the bottom of the structure in a very high radioactive location [es

Two tools have been developed for use by the nuclear industry: the Deep Kerf tool and the Cleaner/Scarifier tool. The Deep Kerf tool is designed to cut through thick, reinforced concrete structures to facilitate their decommissioning. It employs the abrasive-waterjet (AWJ) cutting technology. The basis of the system is a rotary nozzle that makes a slot in the concrete wide enough to accommodate the cutting tool as it advances. In this program, concrete as thick as 1.5 m was cut through from one side. A shroud and vacuum system covers the opening of the slot during cutting to contain the spoils with greater than 99% efficiency. The Cleaner/Scarifier tool was designed for removing the surface layers of contaminated concrete and decontaminating metal surfaces. It uses ultrahigh-pressure waterjets mounted on a rotating arm to remove or clean the target surface. Spoils recovery with a shroud and vacuum system is over 99% complete for both horizontal and vertical surfaces

Laser beam cutting of sheet metal requires an assist gas to blow away the molten material. Since the assist-gas dynamics influences the quality and speed of the cut, the orientation of the gas nozzle with respect to the kerf is also expected to be important. A 1 kW cw CO2 laser with nitrogen assist gas was used to cut mild steel sheet of 1 to 4 mm thickness, using a sonic coaxial nozzle as a baseline. Off-axis nozzles were oriented from 20 deg to 60 deg from normal with exit Mach numbers from 1 to 2.4. Results showed maximum cutting speed at a 40 deg nozzle orientation. Shadowgrams of a geometrically-similar model kerf then revealed a separated shock wave-boundary layer interaction within the kerf for the (untilted) coaxial nozzle case. This was alleviated, resulting in a uniform supersonic flow throughout the kerf and consequent higher cutting speeds, by tilting the nozzle between 20 deg and 45 deg from the normal. This result did not depend upon the exit Mach number of the nozzle. (Research supported by NSF Grant DMI-9400119.)

The objective of the present study is to analyze and compare the cutting performance of segmented diamond blades when dry-cutting concrete. A cutting criteria is proposed to characterize the wear of the blades by measuring the variation of the external diameter and the weight loss of the blade. The results exhibit the cutting blade SB-A, which has twice the density of diamonds and large contact area, exhibits less wear even though the material removal rate is higher compared with the other two cutting blades. Additionally, the surface topography of the different blades is evaluated to examine the impact of wear depending on the surface profile and the distribution of the diamonds in the blade's matrix. Large number of diamonds pull-out are found in blades type SB-C, which additionally shows the worst wear resistant capability. As a conclusion, the cutting efficiency of the blade is found to be related to the density of embedded diamonds and the type of the surface profile of the cutting blade after reaching the stop criteria.

. The project aims to reduce the amount of manual labour as well as production time by applying robots to cut expanded polystyrene (EPS) moulds for the concrete to form doubly curved surfaces. The scheme is based upon the so-called Hot Wire or Hot Blade technology where the surfaces are essentially swept out...

. The shuttle layout problem is frequently solved in two phases: first, a floorplan of the shuttle is generated. Then, a cutting plan is found which minimizes the overall number of wafers needed to satisfy the demand of each die type. Since some die types require special production technologies, only compatible...

We consider discrete protocols for the classical Steinhaus cake cutting problem. Under mild technical conditions, we show that any deterministic strategy-proof protocol in the standard Robertson-Webb query model is dictatorial, that is, there is a fixed agent to which the protocol allocates the e...

Abstract. The observation that about 90% of Eritrean women were circumcised in 2002 increased interest to understand the trends, determinants, and consequences of female genital cutting (FGC). The study used data from the 2002 EDHS and the 2003 Female Genital Mutilation Survey to consider factors that influence the ...

It is shown that the Pomeron-Pomeron cut in γγ scattering has natural C parity and conspires, in contrast to the Pomeron pole which is evasive, and has natural parity and C parity. The constraints this places upon the invariant amplitudes are analyzed

"The Cern particle-physics lab near Geneva is to slash about 260m euro ($340m) from its budget for 2011-2015. The cut, which was approved by Cern's council last month, will require the lab to scale back research into future particles accelerators" (0.5 page)

We consider discrete protocols for the classical Steinhaus cake cutting problem. Under mild technical conditions, we show that any deterministic strategy-proof protocol in the standard Robertson-Webb query model is dictatorial, that is, there is a fixed agent to which the protocol allocates...

The forces during cryosectioning were measured using miniature strain gauges attached to a load cell fitted to the drive arm of the Porter-Blum MT-2 cryomicrotome. Work was calculated and the data normalized to a standard (1 mm X 1 mm X 0.5 micrometer) section. Thermal energy generated was also calculated. Five parameters were studied: cutting angle, thickness, temperature, hardness, and block shape. Force patterns could be divided into three major groups thought to represent cutting (Type I), large fracture planes greater than 10 micrometer in length (Type II), and small fracture planes less than 10 micrometer in length (Type III). Type I and Type II produced satisfactory sections. Work in cutting ranged from an average of 78.4 muJ to 568.8 muJ. Cutting angle and temperature had the greatest effect on sectioning. Heat generated would be sufficient to cause through-section melting for 0.5 micrometer thick sections assuming the worst possible case, namely that all heat went into the section without loss. Presence of a Type II pattern (large fracture pattern) is thought to be presumptive evidence against thawing.

Full Text Available A cut set is a collection of component failure modes that could lead to a system failure. Cut Set Analysis (CSA is applied to critical systems to identify and rank system vulnerabilities at design time. Model checking tools have been used to automate the generation of minimal cut sets but are generally based on checking reachability of system failure states. This paper describes a new approach to CSA using a Linear Temporal Logic (LTL model checker called BT Analyser that supports the generation of multiple counterexamples. The approach enables a broader class of system failures to be analysed, by generalising from failure state formulae to failure behaviours expressed in LTL. The traditional approach to CSA using model checking requires the model or system failure to be modified, usually by hand, to eliminate already-discovered cut sets, and the model checker to be rerun, at each step. By contrast, the new approach works incrementally and fully automatically, thereby removing the tedious and error-prone manual process and resulting in significantly reduced computation time. This in turn enables larger models to be checked. Two different strategies for using BT Analyser for CSA are presented. There is generally no single best strategy for model checking: their relative efficiency depends on the model and property being analysed. Comparative results are given for the A320 hydraulics case study in the Behavior Tree modelling language.

The problem in optimising the laser cutting process is outlined. Basic optimisation criteria and principles for adapting an optimisation method, the simplex method, are presented. The results of implementing a response function in the optimisation are discussed with respect to the quality as well...

With approximately 450 snow plow trucks, the Maine Department of Transportation (MaineDOT) uses in : excess of 10,000 linear feet of plow cutting edges each winter season. Using the 2008-2009 cost per linear : foot of $48.32, the Departments total co...

Based on the Baikov representation, we present a systematic approach to compute cuts of Feynman Integrals, appropriately defined in d dimensions. The information provided by these computations may be used to determine the class of functions needed to analytically express the full integrals.

Page 1 of 3 Researchers are in uproar after a recently established quango unveiled a series of cuts and abandoned some projects altogether because of an estimated 80m funding shortfall. Martin Rees, the Astronomer Royal, argues that Britain will pay a far higher price if it scraps vital projects now

The ability of the following external factors on inducing root formation on leafless cuttings of Salix caprea L. was investigated: root promoting hormones, centrifugation, diffusate (plant sap), and planting substrates. The greatest number of rooted Salix caprea cuttings was obtained after treatment with 40 ppM IBA during 24 hours. However, the young root systems were very susceptile to fungal infections. Thus, the initial positive effect of the root promoting hormone was neutralized by the low survival among the test plants. Neither centrifugation nor diffusate treatment of the cuttings increased the rooting percentage further. Hormone treatment of young shoots or buds grown in water resulted in vigorous root formation on all stem sections placed below the water surface. Practically all vegetative buds on each sprout gave rise to new plants. Planting in coarse sand (3 mm) resulted in healthier plants and stronger root systems compared with cuttings rooted in peat-sand mixture (75/25 vol %), agar, and fine grained sand. Roots developed in coarse sand were spread along a longer stem section compared with roots formed in a compact substrat. Plants with a despersed root system tended to be less harmed by fungal infections than plants with all roots concentrated at the base. It is concluded that the main problem associated with vegetative propagation of Salix caprea, in the traditional manner, is the susceptibility of the hormontreated cuttings against fungal infections and not the root formations step in it self. Hormone treatment of young shoots or buds is proposed as one conceivable solution on this problem.

Full Text Available The goal of this study was to evaluate highmoisture saturation environments for rootingcuttings from guava. The experiment was carriedout in randomized complete block design infactorial scheme composed by guava tree cultivars(Paluma and Cortibel 6, types of cuttings(softwood cuttings and minicuttings, androoting environments (conventional chamberwith intermittent nebulization and minichambers constituted of plastic containers. Fourrepetitions were used and the experimental plotswere composed by ten softwood cuttings or minicuttings.Rooting of ‘Paluma’ ranged between77.5 and 97.5 % and of ‘Cortibel 6’ between2.5 and 57.5%, depending on the environmentand the propagation technique.

After inspecting a one of the most important pipelines in Colombia, using intelligent tool, the pipe sections were selected that presented losses of thickness which probably they would be risking integrity of the same one and after, these sections were cut and replaced. To one of the cut sections a study with the objective was made him establish the present forms of corrosion and to determine the phenomena that influenced the presence of the damages. For this study were moderate thicknesses of the wall of the tube and was determined the criticality comparing it with its nominal thickness, according to Standard ASME B - 31G. Taking advantage of the presence solids in the surface, one became both, physical and chemical analysis, DRX and elementary analysis, with the objective to determine its origin and to correlate it with the types of corrosion that were in the line. The morphology that determined were Microbiological Influenced Corrosion, Erosion - Corrosion, Pitting and CO2 corrosion. Then, from all this information the analysis becomes of risks by internal corrosion in pipeline, the plan of mitigation and the plans of monitoring and inspection of the line to avoid the presence of anyone of these forms of corrosion in the future immediate. (author)

Full Text Available Machine tool chatter is a dynamic instability of the cutting process. Chatter results in poor part surface finish, damaged cutting tool, and an irritating and unacceptable noise. Exten¬sive research has been undertaken to study the mechanisms of chatter formation. Efforts have been also made to prevent the occurrence of chatter vibration. Even though some progress have been made, fundamental studies on the mechanics of metalcutting are necessary to achieve chatter free operation of CNC machine tools to maintain their smooth operating cycle. The same is also true for Vertical Machining Centres (VMC, which operate at high cutting speeds and are capable of offering high metal removal rates. The present work deals with the effect of work materials, cutting conditions and diameter of end mill cutters on the frequency-amplitude characteristics of chatter and on machined surface roughness. Vibration data were recorded using an experimental rig consisting of KISTLER 3-component dynamometer model 9257B, amplifier, scope meters and a PC. Three different types of vibrations were observed. The first type was a low frequency vibration, associated with the interrupted nature of end mill operation. The second type of vibration was associated with the instability of the chip formation process and the third type was due to chatter. The frequency of the last type remained practically unchanged over a wide range of cutting speed. It was further observed that chip-tool contact processes had considerable effect on the roughness of the machined surface.Key Words: Chatter, Cutting Conditions, Stable Cutting, Surface Roughness.

Ductile cutting are most widely used in fabricating high-quality optical glass components to achieve crack-free surfaces. For ultra-precision machining of brittle glass materials, critical undeformed chip thickness (CUCT) commonly plays a pivotal role in determining the transition point from ductile cutting to brittle cutting. In this research, cutting characteristics in nanometric cutting of BK7 and fused silica glasses, including machined surface morphology, surface roughness, cutting force and specific cutting energy, were investigated with nanometric plunge-cutting experiments. The same cutting speed of 300 mm/min was used in the experiments with single-crystal diamond tool. CUCT was determined according to the mentioned cutting characteristics. The results revealed that 320 nm was found as the CUCT in BK7 cutting and 50 nm was determined as the size effect of undeformed chip thickness. A high-quality machined surface could be obtained with the undeformed chip thickness between 50 and 320 nm at ductile cutting stage. Moreover, no CUCT was identified in fused silica cutting with the current cutting conditions, and brittle-fracture mechanism was confirmed as the predominant chip-separation mode throughout the nanometric cutting operation.

We introduce test tube systems based on operations that are closely related to the splicing operations, i.e. we consider the operations of cutting a string at a specific site into two pieces with marking them at the cut ends and of recombining two strings with specifically marked endings. Whereas in the splicing of two strings these strings are cut at specific sites and the cut pieces are recombined immediately in a crosswise way, in CR(cutting/recombination)-schemes cutting can happen independently from recombining the cut pieces. Test tube systems based on these operations of cutting and recombination turn out to have maximal generative power even if only very restricted types of input filters for the test tubes are used for the redistribution of the contents of the test tubes after a period of cuttings and recombinations in the test tubes. 10 refs.

This paper contains CO2 laser cutting results in mild and stainless steel with different laser sources. The main factors which affect the cutting speed and quality are the power, the cutting gas and focal point conditions. Keeping the power and cutting gas constant, the focal point conditions have...... is proven at least for oxyfuel cutting of mild steel, whereas fusion cutting of stainless steel is more complicated.Cutting results from 7 different indus-trial laser sources connected to different moving systems, were used to get information about the importance of the Beam Quality Number K and focal spot...... size,for the maximum cutting speed. One of the 7 laser sources with different focal length and thus different minimum spot size, was then used to investigate more in details the importance of the focal spot size cutting stainless steel with high pressure nitrogen. It looks as if there is a strong...

In addition to a high spatial resolution and well characterised dose response, one of the major advantages of radiochromic film as a dosimeter is that sheets of film can be cut into pieces suitable for use as calibration films, and for in vivo and phantom measurements. The cutting of film is typically done using scissors or a guillotine, and this process can be time-consuming, limited in precision, requires extensive handling and does not allow holes to be cut from the film without cutting from an existing edge. This study investigated the use of a Brother ScanNCut hobby cutting system for EBT3 film preparation. The optimal operating parameters (blade size, pressure, speed) that resulted in precise cuts with minimal delamination at cut edges were identified using test cutting patterns. These parameters were then used to cut a large film insert for a stereotactic head phantom for comparison against an insert cut with scissors. While the hobby cutting system caused a wider region of delamination at the film edge (1.8 mm) compared to scissors (1 mm), the hobby cutting system was found to be able to produce reproducible cuts more efficiently and more accurately than scissors. The use of the hobby cutting system is recommended for complex phantom inserts (containing sharp corners or holes for alignment rods) or in situations where large numbers of film pieces need to be prepared.

The aim of this report is to estimate the exposure to various metals and metal compounds and discuss the available information of the possible toxic effects of these metals and compounds. In the first section, some metals are defined as those with either a large or a fast increasing exposure to living organisms. The available information on toxicity is discussed in the second section. In the third section interesting metals are defined as compounds having a large exposure and an apparent insufficient knowledge of their possible toxic effects. Comments on each of these metals are also to be found in the third section. (G.B.)

Full Text Available The ostrich meat has become an interesting source of protein as well as being an alternative to red meat, because of its healthy fatty acid profile, with a high content of polyunsaturated fatty acids and low content of intramuscular fat, which arouses the interest of people who want a low animal fat diet. Ostrich meat is also appreciated by the tenderness, since it is one of the larger impact characteristics on the acceptance of a meat product for consumers. The aim of this study was to evaluate the tenderness of different ostrich meat commercial cuts and certificate that all studied cuts present tenderness acceptable by consumers. The laboratory tests were performed at the Laboratory of Biochemistry of Proteins (FMVZ, being measured shear force of seven commercial cuts of ostrich meat. The cuts were: internal thigh, external thigh, filet plan, filet out, filet small, rump and filet fan. The samples were boiled in water bath controlled by time and temperature. After chilling, fragments of 1.0 x 1.0 x 3.0 cm were removed from samples. Shear force measurements were performed using a mechanical Warner-Bratzler Shear Force equipment. The shear force means were: internal thigh (3.5 kg, external thigh (2.8 kg, filet plan (2.4 kg, filet out (1.6 kg, filet small (3.5 kg, rump (3.3 kg and filet fan (2.0 kg. All the commercial cuts evaluated had very low values of shear force, denoting meat extremely tender. The classification of meat tenderness is based on shear force values, being values below 4.6 kg considered meat with desirable tenderness. All ostrich meat commercial cuts analyzed had shear force values lower than 4.6 kg, being classified as meat of extreme tenderness. The results found in this work allow concluding that ostrich meat can be considered tender. These findings lead us to consider the ostrich meat as an interesting alternative to red meat, in relation to tenderness and healthy fatty acid profile, being favorable for people suffering from

The purpose of this research was to develop models for the prediction of responses from orthogonal metalcutting process that are responsible for the machinability ratings of this technological system. Mild steel work-piece material that is representative sample for various industrial applications was machined. The various ...

Full Text Available For designing optimal polymeric films for modified atmosphere packaging of whole heads as well as for minimally fresh processed (fresh-cut Iceberg lettuce Coolguard, the effect of several cutting grades on respiration rate (RR and ethylene production at 5ºC was studied. According to common industrial practices cutting grades less than 0.5 cm, between 0.5 and 1 cm, and 2 cm length were selected. Results from four experiments were compared to those obtained for whole heads in which a homogenous range of 6 to 8 ml CO2 kg-1 h-1 in RR was found. Compared to whole heads, in fresh-cut lettuce the RR was 2-fold higher. The lowest cutting grade showed the highest respiration rate, and no significant differences in RR among lettuce pieces of intermediate and the highest grades were found. No ethylene production was detected in whole heads, while in minimally processed lettuce pieces only traces were found. For avoiding risks of anaerobic respiration and excessive CO2 levels within packages containing fresh-cut lettuce pieces lower than 0.5 cm length, films with relatively high O2 permeability like standard polypropylene or low-density polyethylene must be selected.;

Full Text Available Objective of this study is to make use easy programming of CNC lathes and to achieve the optimization of part program prepared considering the limiting parameters of the machine. In the present study, a BOXFORD 250 B CNC lathe has been used for experiment and optimization process. The measurement of cutting forces exerted on the cutting tool of CNC lathe has been performed. The cutting forces occurring during the turning operation have been determined for different depth of" cut, feed rate and cutting speed as well as different cutting tools and related data base has been obtained.

Most output parameters in machining, such as cutting forces, temperatures, strains and the work-hardening of the chip material, are directly related to the chip formation process. The characteristics of machining processes can be well understood if the forces and strains during chip formation are known. In this research a lathe tool dynamometer was used to measure cutting forces involved in machining of Steel 1045 and Aluminum 2219 T62. High Speed Steel (HSS), cutting tools with positive and negative rake angles were used. It was observed that more cutting forces are experienced by the cutting tool with positive rake angle as compared to the forces experienced by the cutting tool with negative rake angle. For steel 1045 the cutting forces using positive rake angle cutting tool were much higher. This suggested that for harder materials using a negative rake angle is more suitable for cutting. (author)

In 1992, the Bonneville Power Administration spent $361 million in capital on a system to transmit electricity. By 1998, it was spending about one-third that amount: $123 million. In 1992, BPA`s expenses for managing, operating and maintaining the transmission system ran $160 million. By 1998, BPA had cut expenses to $128 million. Maintenance costs alone were cut 28%. In 1992, management of the grid was split into six organizations. Today, there is one. About 2,900 people worked for transmission in October 1992. By February 1998, the Transmission Business Line (TBL) employed 1,855. Transmission in 1992 for the most part meant new towers, lines and substations. Today it means computers, digital communications and electronic controls.

We prove several geometric theorems using tools from the theory of convex optimization. In the Riemannian setting, we prove the max flow-min cut (MFMC) theorem for boundary regions, applied recently to develop a ‘bit-thread’ interpretation of holographic entanglement entropies. We also prove various properties of the max flow and min cut, including respective nesting properties. In the Lorentzian setting, we prove the analogous MFMC theorem, which states that the volume of a maximal slice equals the flux of a minimal flow, where a flow is defined as a divergenceless timelike vector field with norm at least 1. This theorem includes as a special case a continuum version of Dilworth’s theorem from the theory of partially ordered sets. We include a brief review of the necessary tools from the theory of convex optimization, in particular Lagrangian duality and convex relaxation.

Female genital mutilation/cutting (FGM/C) is a cultural practice involving several types of external female genitalia cutting. FGM/C is known to occur in all parts of the world but is most prevalent in 28 countries in Africa and the Middle East and among immigrant communities in Europe, Australia, New Zealand, Canada, and the United States. Studies of FGM/C suffer from many methodological problems including inadequate analysis and an unclear reporting of results. The evidence to link FGM/C to infertility is weak. The management of epidermal clitoral inclusion cysts includes expensive investigations like comprehensive endocrinology tests and MRI resulting in unnecessary anxiety due to delay in surgical treatment. Similarly, unnecessary cesarean sections or rupture of the infibulation scar continue to occur because of the inadequate use of intrapartum defibulation. A significant amount of efforts is required to improve and correct the inadequate care of FGM/C women and girls.

Unitarity cuts are widely used in analytic computation of loop amplitudes in gauge theories such as QCD. We expand upon the technique introduced in hep-ph/0503132 to carry out any finite unitarity cut integral. This technique naturally separates the contributions of bubble, triangle and box integrals in one-loop amplitudes and is not constrained to any particular helicity configurations. Loop momentum integration is reduced to a sequence of algebraic operations. We discuss the extraction of the residues at higher-order poles. Additionally, we offer concise algebraic formulas for expressing coefficients of three-mass triangle integrals. As an application, we compute all remaining coefficients of bubble and triangle integrals for nonsupersymmetric six-gluon amplitudes

The Japanese National Center of INIS has been submitting MF to the INIS Headquarters since 1971. In 1977, the center was requested to mount a cutting mark on the master MF on the basis of the NMA-MS-5 Standard which had never been adopted in Japan. Its new method was investigated in the collaboration with the microfilming companies. Consequently the best way was found by exposing the light on a spot of the film at photographing. But it took much time to make them in use, therefore, its tentative way was taken by painting the black ink manually on the master fiche. While the microfilming companies made an effort to adapt the camera to put marks other than former one. After bringing to completion, the cutting marks satisfied with the standard came to be automatically mounted on the master fiches. (author)

A program was initiated to develop the arc saw as a tool capable of removing the end fittings from spent nuclear fuel bundles. A special arc saw for this purpose was designed, installed at the Pacific Northwest Laboratory and satisfactorily operated to remove end fittings from simulated, nonradioactive fuel bundles. The design of the arc saw included consideration of the cutting environment, power supply size, control equipment, and work piece size. Several simulated fuel bundles were cut to demonstrate that the arc saw met design specifications. Although the arc saw development program was curtailed before significant performance data could be collected, tests indicate that the arc saw is a good means of cropping spent fuel bundles and is well suited to remote operation and maintenance

Waterjet cutting is an advanced technology. It consists of a cutting tool that uses a very thin stream of ultra-high-pressure water forced at high velocity through a very small nozzle, creating a very sharp knife. We report on the first experimental use of waterjet technology to reshape the cornea. The system was used in vitro on 10 bovine eyes, and in vivo on 10 albino rabbit eyes. Using the waterjet keratome (Lipshitz-Bass knife, LBK) lamellar corneal incisions were performed. Histological examinations were performed. A waterjet stream was found to be capable of incising corneas at relatively low energy levels (4000 PSI). Good surface quality could be obtained, and there was no collateral damage to the remaining portion of the cornea, lens, or retina. In the in vivo experiments, the epithelium healed within 48 hours. These preliminary experiments suggest that waterjet technology can be an effective instrument for reshaping the cornea.

Full Text Available In this paper, we discuss the use of graph-cuts to merge the regions of the watershed transform optimally. Watershed is a simple, intuitive and efficient way of segmenting an image. Unfortunately it presents a few limitations such as over-segmentation and poor detection of low boundaries. Our segmentation process merges regions of the watershed over-segmentation by minimizing a specific criterion using graph-cuts optimization. Two methods will be introduced in this paper. The first is based on regions histogram and dissimilarity measures between adjacent regions. The second method deals with efficient approximation of minimal surfaces and geodesics. Experimental results show that these techniques can efficiently be used for large images segmentation when a pre-computed low level segmentation is available. We will present these methods in the context of interactive medical image segmentation.

Evidence suggests that some consumers react to promotion signals without considering relative price information. We adopt Petty and Cacioppo's Elaboration Likelihood Model (ELM) to explain this behavior in terms of the ELM's peripheral route to pursuasion in which the promotion signal is taken as a cue for a price cut. Experimental results show that low need for cognition individuals react to the simple presence of a promotion signal whether or not the price of the promoted brand is reduced, ...

Among the many challenges the NHS currently faces is an urgent need to cut its burgeoning energy costs and, in specialist building management system manufacturer Trend Control Systems' words, its "massive carbon footprint". Part of the solution, the company argues, lies in making better use of existing building energy management systems (BEMS). Optimising their operation and performance can, key account manager John O'Leary explains, bring substantial savings without the need for additional investment.

case scenarios for saw cutting due to their hardness. By definition, hardness is the abrasion resistance of aggregate, which is usually measured...loaders (CTL), or skid steers, are high- flow, rubber-tracked machines with quick disconnect fittings that are used for numerous tasks in the current...between the rates was 57 percent. This is not surprising as chert is much harder and more abrasion resistant than limestone. The Vermeer CC1531 with

Fourteen articles cover a wide range of laser applications in welding, cutting and surface treatment. Future trends are covered as well as specific applications in shipbuilding, the manufacture of heart pacemakers, in the electronics industry, in automobile production and in the aeroengine industry. Safety with industrial lasers and the measurement of laser beam parameters are also included. One article on 'Lasers in the Nuclear Industry' is indexed separately. (U.K.)

Full Text Available This research evaluated the quality of forest harvest using chainsaw, in farms in the south of Espirito Santo state, Brazil, considering aspects of quality and loss of wood left in the strains. A total of 250 m² plots were launched to collect data of forest cut with chainsaw, for evaluating the quality of the cut related mto: presence of skewers; crack damage; strains burst range nonstandard; strains without the notch directional, and the remaining height of the strain, in order to measure the loss of wood held in the strains. The main results were: the spike was present in 21.9% of the strains, the cracks in 17.2% of the strains, non-standard strains in 44.6% of them and unnotched directional strains in 34.5% of the evaluations. To check the influence of the realization of the directional notch on the height of the strains t-test, at 5% probability, has shown that there is an increased contribution to height of the strains, where the cut was made without the directional notch. The amount of wood held in the strains above the recommended maximum was, on average, 2.43 m³.ha-1, representing a loss of R$ 172.53 ha-1. It was verified that the loss of timber remaining in eucalyptus strains was higher in places where, for the logging, there was not done the directional notch. The items evaluated showed uneven quality, indicating the need to improve cutting with chainsaw.

The Health Hazard Evaluation Program of the National Institute for Occupational Safety and Health evaluated a steel building materials manufacturer. The employer requested the evaluation because of concerns about optical radiation hazards from a plasma arc cutting system and the need to clarify eye protection requirements for plasma operators, other employees, and visitors. The strength of the ultraviolet radiation, visible radiation (light), and infrared radiation generated by the plasma arc cutter was measured at various distances from the source and at different operating amperages. Investigators also observed employees performing the plasma arc cutting. Optical radiation above safe levels for the unprotected eyes in the ultraviolet-C, ultraviolet-B, and visible light ranges were found during plasma arc cutting. In contrast, infrared and ultraviolet-A radiation levels during plasma arc cutting were similar to background levels. The highest non-ionizing radiation exposures occurred when no welding curtains were used. A plasma arc welding curtain in place did not eliminate optical radiation hazards to the plasma arc operator or to nearby employees. In most instances, the measured intensities for visible light, UV-C, and UV-B resulted in welding shade lens numbers that were lower than those stipulated in the OSHA Filter Lenses for Protection Against Radiant Energy table in 29 CFR 1910.133(a)(5). [1] Investigators recommended using a welding curtain that enclosed the plasma arc, posting optical radiation warning signs in the plasma arc cutter area, installing audible or visual warning cues when the plasma arc cutter was operating, and using welding shades that covered the plasma arc cutter operator's face to protect skin from ultraviolet radiation hazards.

The metal lagging described is characterized by the fact that it is formed of closed sacks composed of an elastic metal mass, compressed in an outer envelope made of a fine mesh metal fabric. The metal mass is composed of stainless steel wool stuffed into the envelope. This lagging is particularly intended for the thermal protection of the end slab of LMFBR type reactors [fr

Replacement of in-core shroud has been conducted as part of the preventive maintenance program in Tsuruga-1. The EDM (electric discharged machining) and plasma cutting methods were applied to in-core shroud cutting and secondary cutting in the DSP (dryer/separator pool), respectively. The cutting systems were improved in order to decrease radioactive secondary products. 1) Fundamental EDM cutting tests: fundamental EDM cutting tests were carried out in order to study secondary products. It could be presumed that volatile Co-carbonyl compound was generated by using a carbon electrode. The Ag/W electrode was effective as EDM electrode for in-core shroud cutting to prevent generation of Co-carbonyl compound and to decrease the total amount of secondary products. 2) In-core shroud cutting in RPV (reactor pressure vessel): EDM cutting system with the Ag/W electrode and collection system could keep a good environment during in-core shroud cutting in Tsuruga-1. Activity concentration was lower value than limitation of mask charge level, 4E-6 Bq/cm 3 , even near the water surface. 3) Secondary plasma cutting in DSP: the secondary cutting work was successful in the point of reduction of working period and radiation exposure. The amount of radiation exposure was reduced to 60% of the planned value, because of adequate decontamination of the working environment and reduction of number of torch maintenance tasks by improvements of the underwater cutting device

Full Text Available The experiment involved plants of 10 Patio rose cultivars of the National Dendrological Park "Sofiyivka" collection. The methods of propagation by cuttings worked out by Moscow Timiryazev Agricultural Academy were assumed as a basis. Callogenesis and regenerative capacity were estimated in accordance with Z.J. Ivanova scale (1982. The fact is ascertained that the success of rooting substantially depends on particularities of certain Patio rose cultivar. It is advisable to use cuttings from basal and medial parts of stems, with remaining leaves, taken within the last ten-day period of May – the first ten-day period of June. The pretreatment with rhizogenic medium "Kornevin" (reactant — indolebutyric acid is the most effective for rooting cuttings. The optimal for rooting is the two-layered substrate: the lower layer is a multicomponent soil compound of peat, perlite, sod soil and humus in ratio 1:1:1:1; the upper layer consists of sand. Seedlings of Patio roses cultivated in open ground during vegetation period form stems 1.8 times more vigorously than ones grown on the same place where they were rooted. The optimal period to transfer into bed is May. It is reasonable to use top removal in order to form vigorous stem system.

This thesis deals with the segmentation of multimodal brain MRIs by graph cuts method. First, we propose a method that utilizes three MRI modalities by merging them. The border information given by the spectral gradient is then challenged by a region information, given by the seeds selected by the user, using a graph cut algorithm. Then, we propose three enhancements of this method. The first consists in finding an optimal spectral space because the spectral gradient is based on natural images and then inadequate for multimodal medical images. This results in a learning based segmentation method. We then explore the automation of the graph cut method. Here, the various pieces of information usually given by the user are inferred from a robust expectation-maximization algorithm. We show the performance of these two enhanced versions on multiple sclerosis lesions. Finally, we integrate atlases for the automatic segmentation of deep brain structures. These three new techniques show the adaptability of our method to various problems. Our different segmentation methods are better than most of nowadays techniques, speaking of computation time or segmentation accuracy. (authors)

The results are presented of a survey conducted by personnel of the National Center for Excellence in Metalworking Technology (NCEMT) to assess the industrial needs in high pressure water jet cutting (WJC) technology. Survey forms were mailed to approximately 1400 individuals obtained from three mailing lists. The respondents included approximately 200 individuals associated with a variety of industries: 12 percent were WJC equipment suppliers, 40 percent were WJC users, and 48 percent were neither suppliers nor users. The survey addressed five specific areas of WJC technology: research and development, standards, systems, new products, and training and service. Results show that the need having the highest priority is the establishment of a database on WJC that contains the cutting parameters for a wide range of materials. Associated with this objective is the expressed need for an independent demonstration and test center for testing, data generation and operator training. A further need was found for establishing organized efforts in hardware development and research in mechanisms of cutting.

The technique of arc-waterjet cutting had to be progressed so that it is possible to gouge the surface of metallic components of nuclear power plants. With applicable cutting parameters depending on the thickness of the contamination the surface had to be gouged and converted to a granulation that is to remove. A continously pulled out wire electrode strikes an arc to the workpeace by short circuit and melts both. A concentric around the wire placed waterjet is able to wash the liquid metal away. With a computer numeric control it is possible to remove the surface of metal up to a deep penetration of 4 to 5 mm. With arc waterjet gouging a remote-controlled removal of contaminated surface activity in shutdowned nuclear power plants under water is possible. (orig./HP) With 15 refs., 1 tab., 14 figs [de

A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

1. Status of research: With arc waterjet cutting it is possible to cut stainless steel up to a wall thickness of 30 mm under water. An application of this technique in 20 m water depth is possible. 2. Aim of research work: A thermal cutting process which is empolyed in a water depth of 20 m is to be developed. Stainless steel up to a wall thickness of 100 mm must be sectile. Cutting of plane parts with variable wall thickness and geometric must be possible. Pipes and pipe assemblies are to be cut from inside or outside. 3. Method of research: A torch was developed which can melt the work piece with a wire electrode. The ignition of cutting will be done with short circuit with a concentrial around the wire out going water jet the liquid metal will be washed away. 4. Results: It is possible to cut stainless steel under water up to a wall thickness of 100 mm. There is no influence to the cutting process in a water depth of 20 m. 5. Suitability: With arc waterjet cutting remote controlled dismantling of thick-walled components of closed down nuclear power plants under water is possible. (orig.) With 35 refs., 6 tabs., 65 figs [de

The utilization of a cut-mask in semiconductor patterning processes has been in practice for logic devices since the inception of 32nm-node devices, notably with unidirectional gate level printing. However, the microprocessor applications where cut-mask patterning methods are used are expanding as Self-Aligned Double Patterning (SADP) processes become mainstream for 22/14nm fin diffusion, and sub-14nm metal levels. One common weakness for these types of lithography processes is that the initial pattern requiring the follow-up cut-mask typically uses an extreme off-axis imaging source such as dipole to enhance the resolution and line-width roughness (LWR) for critical dense patterns. This source condition suffers from poor process margin in the semi-dense (forbidden pitch) realm and wrong-way directional design spaces. Common pattern failures in these limited design regions include bridging and extra-printing defects that are difficult to resolve with traditional mask improvement means. This forces the device maker to limit the allowable geometries that a designer may use on a device layer. This paper will demonstrate methods to expand the usable design space on dipole-like processes such as unidirectional gate and SADP processes by utilizing the follow-up cut mask to improve the process window. Traditional mask enhancement means for improving the process window in this design realm will be compared to this new cut-mask approach. The unique advantages and disadvantages of the cut-mask solution will be discussed in contrast to those customary methods.

KEYWORDS: : RESEARCH AND DEVELOPMENT : THERMAL CUTTING IS A PROCEDURE THAT IS INTEGRAL TO THE MANUFACTURE AND FABRICATION OF STEEL. THERMAL CUTTING IS PARTICULARLY IMPORTANT IN THE PRODUCTION OF PLATE STEELS, WHERE IT IS COMMONLY USED FOR TRIMMING TH...

In the aircraft parts, the portion of titanium alloy, one of the light-weight and high mechanical strength materials, has been increased in terms of the fuel efficiency. Therefore, the effective technologies in cutting of titanium alloy should be established to promote the material removal rate with high production quality. Multi-edges milling cutters, on which many inserts are helically aligned, have been commercially available for millings of deep sinking in large axial depth of cuts. The paper presents an analytical prediction model to control the cutting force with alignment and geometry of the insert. In the model, three dimensional chip flow on each insert is interpreted as a piling up of the orthogonal cuttings in the planes containing the cutting velocities and the chip flow velocities, where the chip flow direction is determined to minimize the cutting energy. Then, the cutting force is predicted in the determined chip flow model. The cutting tests were conducted to validate the force model.

Graph cut criterion has been proven to be robust and applicable in clustering problems. In this paper the graph cut criterion is applied to construct a supervised dimensionality reduction. A new graph cut, scaling cut, is proposed based on the classical normalized cut. Scaling cut depicts the relationship between samples, which makes it can handle the heteroscedastic and multimodel data in which LDA fails. Meanwhile, the solution to scaling cut is global optimal for it is a generalized eigenvalue problem. To obtain a more reasonable projection matrix and reduce the computational complexity as well, the localized k-nearest neighbor graph is introduced in, which leads to equivalent or better results compared with scaling cut.

In optical materials energy is usually extracted only from the lowest excited state, resulting in fundamental energy-efficiency limits such as the Shockley-Queisser limit for single-junction solar cells. Photon-cutting materials provide a way around such limits by absorbing high-energy photons and 'cutting' them into multiple low-energy excitations that can subsequently be extracted. The occurrence of photon cutting or quantum cutting has been demonstrated in a variety of materials, including semiconductor quantum dots, lanthanides and organic dyes. Here we show that photon cutting results in bunched photon emission on the timescale of the excited-state lifetime, even when observing a macroscopic number of optical centres. Our theoretical derivation matches well with experimental data on NaLaF 4 :Pr 3+ , a material that can cut deep-ultraviolet photons into two visible photons. This signature of photon cutting can be used to identify and characterize new photon-cutting materials unambiguously.

Three algorithms are developed that may be based exclusively on hyperspherically deduced cuts. The algorithms only apply, therefore, to problems structured so that these cuts are valid. The algorithms are shown to be finite.

Large-scale molecular dynamics simulation is performed to study the nano-cutting process of single crystal copper realized by single-point diamond cutting tool in this paper. The centro-symmetry parameter is adopted to characterize the subsurface deformed layers and the distribution and evolution of the subsurface defect structures. Three-dimensional visualization and measurement technology are used to measure the depth of the subsurface deformed layers. The influence of cutting speed, cutting depth, cutting direction, and crystallographic orientation on the depth of subsurface deformed layers is systematically investigated. The results show that a lot of defect structures are formed in the subsurface of workpiece during nano-cutting process, for instance, stair-rod dislocations, stacking fault tetrahedron, atomic clusters, vacancy defects, point defects. In the process of nano-cutting, the depth of subsurface deformed layers increases with the cutting distance at the beginning, then decreases at stable cutting process, and basically remains unchanged when the cutting distance reaches up to 24 nm. The depth of subsurface deformed layers decreases with the increase in cutting speed between 50 and 300 m/s. The depth of subsurface deformed layer increases with cutting depth, proportionally, and basically remains unchanged when the cutting depth reaches over 6 nm.

Tool life is a parameter closely connected to the lubricating effect of a cutting fluid. Long tool life in turning corresponds to good lubrication and a process with good lubrication is preferred, since it normally results in lower tool wear and better surface quality. Cutting forces are mainly...... important for understanding the mechanism of the cutting process itself and to perform in this way data about the influence of the cutting fluids....

International audience; Cutting forces are one of the inherent phenomena and a very significant indicator of themetal cutting process. The work presented in this paper is an investigation of the prediction of these parameters in slotting processes of UNS A92024-T3 (Al-Cu) stacks. So, cutting speed (V) and feed per tooth (fz) based parametric models, for experimental components of cutting force, F(fz,V) have been proposed. These models have been developed from the individual models extracted f...

Synchrotron radiation has reached the stage of practical use, and the application to the wide fields that support future advanced technologies such as spectroscopy, the structural analysis of matters, semiconductor lithography and medical light source is expected. For the optical system of the equipment utilizing synchrotron radiation, the total reflection mirrors of oblique incidence are used for collimating and collecting X-ray. In order to restrain their optical aberration, nonspherical shape is required, and as the manufacturing method with high precision for nonspherical mirrors, a numerically controlled diamond cutting machine was developed. As for the cutting of soft metals with diamond tools, the high precision machining of any form can be done by numerical control, the machining time can be reduced as compared with grinding, and the cooling effect is large in metals. The construction of the cutting machine, the principle of machining, the control system, the method of calculating numerical control data, the investigation of machinable forms and the result of evaluation are reported. (K.I.)

Full Text Available Turning process is the removal of metal from the outer diameter of a rotating cylindrical workpiece. Turning is used to reduce the diameter of the workpiece, usually to a specified dimension, and to produce a smooth finish on the metal. This research investigates the effect of feed rate, spindle speed, tool overhang and tool dimensions toward vibration amplitude and surface roughness on turning process. This study uses both statistical and graphical analysis of the data collected. The experimentation was carried out on conventional lathe machine with straight turning operation. Material used as workpiece was St.60 carbon steel which was turned with HSS tool bit with the dimension of 3/8 Inches and ½ Inches. Cutting parameters varied by spindle speed, feed rate, and tool overhang, while the depth of cut is maintained at a depth of 0.5 mm. The vibration data of cutting tool obtained from a transducer (vibrometer mounted at a distance of 10 mm from the tip of the cutting tool during the cutting process takes place, whereas the surface roughness data obtained from measurements of surface roughness apparatus after turning process. The results showed that, The effect of feed rate, spindle speed, tool overhang, and tool dimension simultaneously towards vibration amplitude and surface roughness has a grater effects on the use of 3/8 inches cutting tool than ½ inches cutting tool. With the use of the same tool dimensions obtained that, The most influential parameters on the vibration amplitude is tool overhang while the most influential parameter on surface roughness value is feed rate.

Full Text Available This work evaluated the performance of clonal olive tree gardens in successive cuts aiming cutting propagation. The clonal garden was installed in March 2006, in grooves 40 cm deep. Two cultivars (Ascolano 315 and Arbequina were evaluated and cut in 2007, 2008 and 2009. The test was carried out in split plot in time in a randomized block design with five replications. The plots were composed of three lines, one meter spaced between them, three plants in each line, spaced 0,5 m from each other, totaling nine plants per plot, being evaluated only the three most vigorous plants. For evaluation, three plants were pruned 20 cm height above soil, after 12 months of cultivation, it was evaluated the yield of cuttings with four knots and two pairs of leaves; plants height (m, torso diameter the 20 cm height of the soil (cm; branches length (m; and total green mass accumulated (kg. In most features evaluated, the best results were observed in the ‘Ascolano 315’. The successive cuts may be extended over a three year period. The parameter estimates indicate that plants of both cultivars y responded satisfactorily to regrowth.

The light weight property as well as high corrosion resistance of aluminium alloy has increased their demand especially in automobile industries. Aluminium alloy as a matter of fact has a low melting point and high ductility that severely adhere to the cutting tool surface and cause deterioration of chip evacuation. This problem often resulting in tools breakage. In this paper, in order to impart functions of anti-adhesion, we propose a technique by controlling the grinding marks micro texture on the tool surface by using the blast polishing treatment without any coating technologies. The results show that the tool which underwent polishing treatment reduces the cutting force as well as the aluminium adherence during the initial cutting process, and become worst as the process cutting continues. These results indicate that grinding mark texture improves the anti-adhesion by reducing the contact area during cutting and provide storage for the lubricant. In addition, too much polishing on the tool surface may remove these textures and resultantly worsen the tool performance. (paper)

The light weight property as well as high corrosion resistance of aluminium alloy has increased their demand especially in automobile industries. Aluminium alloy as a matter of fact has a low melting point and high ductility that severely adhere to the cutting tool surface and cause deterioration of chip evacuation. This problem often resulting in tools breakage. In this paper, in order to impart functions of anti-adhesion, we propose a technique by controlling the grinding marks micro texture on the tool surface by using the blast polishing treatment without any coating technologies. The results show that the tool which underwent polishing treatment reduces the cutting force as well as the aluminium adherence during the initial cutting process, and become worst as the process cutting continues. These results indicate that grinding mark texture improves the anti-adhesion by reducing the contact area during cutting and provide storage for the lubricant. In addition, too much polishing on the tool surface may remove these textures and resultantly worsen the tool performance.

Effect of the cutting position, terminal and subterminal, and rooting substance on the rooting of cuttings of two Cyclopia species (Cyclopia genistoides and C. intermedia) taken in winter, spring or summer was studied under controlled glasshouse conditions. Cuttings taken in summer, irrespective of the species, rooted better ...

The research program deals on the definition of tools used for dismantling steam generator tubes bundle of PWR and on tool used for cutting pipes of great diameter by using the process of cutting by electrical arc saw. The remote tools are used for cutting by the interior pipes of contamined circuits [fr

Cut flowers show a wide variance of keepability. The market demands more and more a guaranteed quality. Therefore, methods must be developed to predict vase life of cut flowers. Chrysanthemum ( Dendranthema x grandiflorum Tzvelev) and some other cut flowers suffer from

This research validated the framework for the standardized and simplified cutting bill presented in an earlier paper. The cutting bill validation was carried out in two ways. First, all 20 of the cutting bill's part groups were examined to determine if significant yield influences resulted from changing specific part sizes within the boundaries of a given part...

Thirty human enamel blocks and microscope glass slides of 0.5mm thickness were randomly divided into these three groups. The time taken to cut a hole through the glass slide and for the cutting of human enamel blocks was recorded, the cutting time was fixed at 15 s. The depths of the cavities were measured using a ...

In stands of mixed white and red fir in northeastern California, cuttings for natural regeneration became well stocked with seedlings within 2 to 5 years after cutting. Seed tree and shelterwood cuttings, clearcut strips not more than 3 chains (60 m) wide, and patches not exceeding 4 chains (80 m) width were studied. Incidence of damage among residual trees in or...

Full Text Available Ceramic matrix composites (“CMC” with a strong fibre-matrix interface can be made damage-tolerant by introducing a highly porous matrix. Such composites typically have only a low interlaminar shear strength, which can potentially promote damage when preparing specimens or components by cutting. In order to investigate the damage induced by different cutting methods, waterjet cutting with and without abrasives, laser-cutting, wire eroding and cutoff grinding were used to cut plates of two different CMCs with a matrix porosity up to 35 vol.-%. For each combination of cutting method and composite, the flexural and interlaminar shear strength of the resulting specimens was determined. Additionally, the integrity of the regions near the cut surfaces was investigated by high-resolution x-ray computer tomography. It could be shown that the geometrical quality of the cut is strongly affected by the cutting method employed. Laser cut and waterjet cut specimens showed damage and delaminations near the cut surface leading to a reduced interlaminar shear strength of short bend bars in extreme cases.

Jun 14, 2010 ... The specific objectives of this study were to evaluate the effect of storage duration on the survival rate of rooted cuttings and to determine the rooting and survival rates of non-rooted cuttings for two standard carnation cultivars (that is., Dianora and Vittorio). The survival rates of rooted cuttings showed ...

While the performance of YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO)-based coated conductors under dc currents has improved significantly in recent years, filamentization is being investigated as a technique to reduce ac loss so that the 2nd generation (2G) high temperature superconducting (HTS) wires can also be utilized in various ac power applications such as cables, transformers and fault current limiters. Experimental studies have shown that simply filamentizing the superconducting layer is not effective enough to reduce ac loss because of incomplete flux penetration in between the filaments as the length of the tape increases. To introduce flux penetration in between the filaments more uniformly and further reduce the ac loss, virtual transverse cross-cuts were made in superconducting filaments of the coated conductors fabricated using the metal organic chemical vapor deposition (MOCVD) method. The virtual transverse cross-cuts were formed by making cross-cuts (17 - 120 {micro}m wide) on the IBAD (ion beam assisted deposition)-MgO templates using laser scribing followed by depositing the superconducting layer ({approx} 0.6 {micro}m thick). AC losses were measured and compared for filamentized conductors with and without the cross-cuts under applied peak ac fields up to 100 mT. The results were analyzed to evaluate the efficacy of filament decoupling and the feasibility of using this method to achieve ac loss reduction.

Full Text Available Purpose: The main objective of this study is to develop a model for solving the one dimensional cutting stock problem in the wood working industry, and develop a program for its implementation. Design/methodology/approach: This study adopts the pattern oriented approach in the formulation of the cutting stock model. A pattern generation algorithm was developed and coded using Visual basic.NET language. The cutting stock model developed is a Linear Programming (LP Model constrained by numerous feasible patterns. A LP solver was integrated with the pattern generation algorithm program to develop a one - dimensional cutting stock model application named GB Cutting Stock Program. Findings and Originality/value: Applying the model to a real life optimization problem significantly reduces material waste (off-cuts and minimizes the total stock used. The result yielded about 30.7% cost savings for company-I when the total stock materials used is compared with the former cutting plan. Also, to evaluate the efficiency of the application, Case I problem was solved using two top commercial 1D-cutting stock software. The results show that the GB program performs better when related results were compared. Research limitations/implications: This study round up the linear programming solution for the number of pattern to cut. Practical implications: From Managerial perspective, implementing optimized cutting plans increases productivity by eliminating calculating errors and drastically reducing operator mistakes. Also, financial benefits that can annually amount to millions in cost savings can be achieved through significant material waste reduction. Originality/value: This paper developed a linear programming one dimensional cutting stock model based on a pattern generation algorithm to minimize waste in the wood working industry. To implement the model, the algorithm was coded using VisualBasic.net and linear programming solver called lpsolvedll (dynamic

-fostering experiment designed to address the influences of genotype and social rearing environment upon individual and social immune defenses. We used a multiply mating leaf-cutting ant, enabling us to test for patriline effects within a colony, as well as cross-colony matriline effects. The worker's father influenced...... social defense, a Pseudonocardia bacteria that helps to control pathogens in the ants' fungus garden, showed a significant colony of origin by rearing environment interaction, whereby ants that acquired the bacteria of a foster colony obtained a less abundant cover of bacteria: one explanation...

High pressure water cutting techniques have a wide range of applications to the American space effort. Hydroblasting techniques are commonly used during the refurbishment of the reusable solid rocket motors. The process can be controlled to strip a thermal protective ablator without incurring any damage to the painted surface underneath by using a variation of possible parameters. Hydroblasting is a technique which is easily automated. Automation removes personnel from the hostile environment of the high pressure water. Computer controlled robots can perform the same task in a fraction of the time that would be required by manual operation.

High Performance Grinding and Advanced Cutting Tools discusses the fundamentals and advances in high performance grinding processes, and provides a complete overview of newly-developing areas in the field. Topics covered are grinding tool formulation and structure, grinding wheel design and conditioning and applications using high performance grinding wheels. Also included are heat treatment strategies for grinding tools, using grinding tools for high speed applications, laser-based and diamond dressing techniques, high-efficiency deep grinding, VIPER grinding, and new grinding wheels.

Full Text Available In industry different methods of surface hardening are widely used to increase reliability and durability of friction unit parts. Among these methods are areas of focus based on deformcutting technology (DC i.e. method of chip-free mechanical treatment.It is shown that DC method allows us to produce through- or partial-hardening surface layers of a large thickness (0,4…1.5mm on steel with no additional heat sources. The standard metal-cutting equipment and common tools are used for deform-cutting process.The significant heat generation in the deform-cutting zone and mechanical effect from the tool allow us to heat undercut layers to the phase transformation point to have the hardening structure as a result of heat removal to the cold balk. The hardening structure formation occurs at significant heating and cooling rate (106C/c with large degrees and rates of strain.The deform-cutting modes and working face tool grinding determine the type and properties of the hardening structure. To produce the hardening structure would require the heat transfer and force action augmentation while treatment.These researches deal with through- and partial surface hardening samples produced by turning steel 35 shafts. While through hardening the phase transformation carry among the whole thickness of the undercut layer; while partial hardening the hardening interlayer formed on the side of the cutting tool contact.The depth of hardening zone of samples with through hardening layers is 0,5 mm; the depth of hardening zone of partial hardening samples is 0,8 mm. Micro-hardness of the through hardening layers is 653 HV0,1 and 485 HV0,1 for the partial hardening layers. The metallographic analysis shows that the hardening zone formed while deform cutting has disperse structure; there are ferrite ghosts in it.The tempering at temperatures of 200 – 700C showed that the micro-hardness of the hardening structures formed while deform cutting is larger than the micro

An investigation on the effect of different cutting fluids in reaming is presented. The performance of three water based cutting fluids and one cutting oil was compared to that of a reference water based commercial product by measurement of cutting forces, surface roughness and part accuracy. Three...... subsequent reaming operations were carried out on austenitic stainless steel using high-speed-steel and solid carbide tools. The tested fluids were all significantly different from the reference fluid in at least some of the tested conditions. Significant differences down to 2 percent in cutting forces and 6...

Full Text Available The most commonly used methods for committing suicide in India are hanging, poisoning, burns, jumping from height, drowning, firearm injuries, stab injuries etc. Cut throat injuries using a sharp weapon is the least frequent suicidal method. Tentative cut marks are common in suicidal deaths. Committing suicide by cutting their throat without hesitation marks is a very rare occurrence. We present a case of 32 year old male, suffering from psychiatric illness brought dead to tertiary care hospital with suicidal cut throat injury and not associated with tentative cuts and tailing of wound.

of both of the new lasers against traditional CO2-laser. The results showed that the new lasers offer a great potential in improving the productivity of cutting phase with an acceptable edge quality. This is emphasized in thin sheets of 1.3 and 2.3 mm thickness. In that case the width of the cut kerf...... of each thickness. The results were very promising and it can be stated that these new laser types have a great potential in cutting and will probably gain a considerable market share not only in 3D cutting applications but also in ordinary flat sheet cutting....

TiC-TiB 2 composites have been produced via SHS technique starting from low cost raw materials like TiO 2 , B 4 C, Mg. The influence of the diluent phase (Mg, TiC) content on combustion temperature has been investigated. The use of magnesium as the reductant phase allowed acid leaching of the undesired oxide product (MgO), leaving pure hard materials with fine particle size suitable to be employed in cutting tools manufacturing through cold pressing and sintering route. The densification has shown to be strongly dependent on the wetting additions. The influence of the metal binder and wetting additions on the sintering process has been investigated. A characterization of the obtained materials was performed by the point of view of cutting tools life (hardness, toughness, strength). (author)